2016 Prospects: Seattle Mariners Top 10 Prospects

Last year's Mariners list

The State of the System: Over the past 25 years, Seattle has developed some of the best players in baseball history. The next Mariners legend is most likely not on this list. Seattle’s pitching depth is nonexistent and there’s as little talent in the upper minors as in any system.

The Top Ten

1. OF Alex Jackson
2. RHP Edwin Diaz
3. LHP Luiz Gohara
4. 1B D.J. Peterson
5. LHP Ryan Yarbrough
6. OF Luis Liberato
7. SS Drew Jackson
8. OF Boog Powell
9. OF Tyler O'Neill
10. RHP Nick Neidert

1. Alex Jackson, OF
DOB: 12/25/1995
Height/Weight: 6’2” 210 lbs.
Bats/Throws: R/R
Drafted/Acquired: Drafted 6th overall in the 2014 MLB Draft, Rancho Bernardo HS (San Diego, CA); signed for $4.2 million
Previous Ranking(s): #2 (Org.)
2015 Stats: .207/.316/.365, 8 HR, 3 SB in 318 PA at short-season Everett and Low-A Clinton
Future Tools: 60 power, 55 hit, 55 arm
Role: 55—Above-average right fielder

An advanced offensive skill set was one of the reasons Jackson was considered the best prep hitter in the country in 2014. Funny what hitting .157 in the Midwest League will do to perception.

Yes, Jackson stunk worse than the dog food factory in Clinton, but there’s still room for optimism. He has impressive bat speed, and a swing path that helps him create leverage and extension to spray bullets all over the park. The swing doesn’t have a ton of loft, but there’s still plus power potential because of his ability to backspin balls. He drew his share of walks, but multiple sources said he failed to recognize secondary offerings well, and there was more swing-and-miss than anticipated in his first full year in the system.

Jackson has below-average speed, which is to be expected from a former catcher. He has a strong arm and takes good routes, however—a combination that ought to allow him to play a competent corner outfield.

There’s no question Jackson was disappointing in 2015, but he’s a prime candidate to rebound, assuming he makes the necessary adjustments. There was just too much offensive upside shown in high school to believe he can’t.

Bret Sayre's Fantasy Take: The shine was quick to wear off on Jackson, especially in fantasy circles, but the potential that got him taken in the first round of dynasty drafts just one year ago is still present; it’s just buried under some additional risk. The prospect of Safeco still stinks, but even there, he could be a .275 hitter with 25 homers. That’s borderline OF2 potential.

Major league ETA: 2018

2. Edwin Diaz, RHP
DOB: 03/22/1994
Height/Weight: 6’3” 165 lbs.
Bats/Throws: R/R
Drafted/Acquired: Drafted in the third round of the 2012 Draft, Caguas Military Academy (Caguas, PR); signed for $300,000
Previous Ranking(s): #5 (Org.)
2015 Stats: 3.82 ERA, 141.1 IP, 46 BB, 145 K at High-A Bakersfield and Double-A Jackson
Future Tools: 65 fastball, 55 slider
Role: 50+—Potential mid-rotation starter/high-leverage reliever

Diaz is still more projection than product, but he’s made significant strides over the past few seasons and is now the best pitching prospect in the system. His arm strength is elite; despite being wafer-thin he can get his four-seam fastball into the mid-90s consistently, occasionally touching 98, with some late life. His 83-85 mph slider will flash plus but is more comfortably an above-average offering. He can locate it for strikes when he’s not overthrowing it, and there’s enough late break to get swinging strikes. His change will likely never reach the level of the fastball or slider, but it’s a competent pitch with just enough deception created by his arm speed to keep hitters honest. He has improved his ability to repeat his delivery, and though not a control artist, he should throw enough strikes to toe the rubber every fifth day.

The biggest concern with Diaz going forward is his size. He’s shown solid durability early on, but because of his diminutive stature there are major questions about whether his body can handle the rigors of a full workload. If he does move to the bullpen, he’s a potential closer, but there’s obviously more value in a potential No. 3 starter. If everything breaks right, that’s what Diaz becomes.

Fantasy Impact: The impact of a Safeco future certainly does more to emphasize the pitchers on this list, but given the wheelin’ and dealin’ style of new General Manager Jerry Dipoto, maybe we shouldn’t give it too much credence right now. If Diaz is a starter, which as Chris mentioned above, is not a given at all, he’ll likely top out as a strong SP4 who is better in the ratio department than in strikeouts.

Major league ETA: 2017

3. Luiz Gohara, LHP
DOB: 07/31/1996
Height/Weight: 6’3” 240 lbs.
Bats/Throws: L/L
Drafted/Acquired: Signed in August 2012 out of Brazil for $880,000
Previous Ranking(s): #7 (Org.)
2015 Stats: 5.54 ERA, 63.1 IP, 77 H, 38 BB, 67 K at short-season Everett and Low-A Clinton
Future Tools: 60 fastball, 55 slider
Role: 50+—Mid-rotation starter

When the Mariners signed Gohara to the biggest bonus ever for a Brazilian player, they knew he was not a fast-track player. Still, they likely expected a little more progression than this. His arm strength allows him to get up to 98 with his four-seam fastball with some life, sitting 92-94 more consistently . His slider is an average offering, and while it doesn’t have huge break or depth there’s enough bite to fool hitters. His changeup has made significant progress since he entered the system, and some scouts believe it has a chance to be his best pitch when all is said and done. He’s still learning to rein in his delivery and repeat a consistent arm slot, which limits his present command, but the physicality suggests he should ultimately throw enough strikes to remain a starter.

The industry isn’t as high on Gohara, and there are some serious concerns about his weight and work ethic going forward. As one of the few pitchers with any kind of upside, it’s still easy to justify putting the left-hander near the top of this system—even with the noted volatility.

Bret Sayre's Fantasy Take: There’s both more risk and reward (not to mention lead time) with Gohara than there is with Diaz, but Gohara remains interesting for fantasy purposes in his own right, despite the ugly stat page. As the only arm with SP3 upside on this list, he should be owned in leagues where 200 prospects are rostered, but he’s not as shiny in dynasty leagues as he used to be.

Major league ETA: 2018

4. D.J. Peterson, 1B/3B
DOB: 12/31/1991
Height/Weight: 6’1” 210 lbs.
Bats/Throws: R/R
Drafted/Acquired: Drafted 12th overall in the 2013 MLB Draft, University of New Mexico; signed for $2.7591 million
Previous Ranking(s): #1 (Org.)
2015 Stats: .223/.287/.344, 7 HR, 5 SB in 407 PA at Double-A Jackson and Triple-A Tacoma
Future Tools: 60 power, 60 arm
Role: 45—Fringe-average regular at first base

After a fantastic 2014 season, Peterson struggled mightily in 2015, and several sources I spoke with believed he didn’t belong in the system’s top 10, much less the top five. Still, Peterson has more than his fair share of supporters, both in the organization and out. He’ll put on shows in batting practice that suggest plus-plus power derived from natural strength and hip rotation, but his approach regressed significantly, and anything that wasn’t straight crippled him. His in-game swing isn’t the same one that impresses in BP: It’s geared for more contact, but because his hands are often late, it doesn’t actually produce consistent or square contact. There’s enough bat speed and linear plane to project an average hit tool, but he’ll have to show more selectivity if he’s going to reach that mark.

Peterson spent all of the Arizona Fall League at first base, and the Mariners appear to have (wisely) given up on him as a third baseman. The arm is plus, but no other skill grades out as even average at the hot corner. That puts enormous pressure on his bat, and nothing Peterson showed in 2015 suggests he’s capable of reaching those heights. He’s just a year removed from being one of the best corner-infield prospects in baseball so you can’t write him off as a major league contributor, but it’s tough to take anybody who looks this bad in a not-small sample seriously as an elite hitting prospect.

Bret Sayre's Fantasy Take: Peterson checked in at no. 36 on the pre-season Dynasty 101, and his stock has tumbled nearly as hard in dynasty leagues as in real life. With a permanent move to first almost assured now, the bar just gets that much higher in fantasy as well. Safeco will mute some of his power, but his ceiling now looks closer to his floor from a year ago—a .260-hitting, 25-homer first baseman.

Major league ETA: Late 2016

5. Ryan Yarbrough, LHP
DOB: 12/31/1991
Height/Weight: 6’5” 205 lbs.
Bats/Throws: R/L
Drafted/Acquired/Bonus: Drafted in the fourth round of the 2014 MLB Draft, Old Dominion University; signed for $40,000
Previous Ranking(s): Unranked
2015 Stats: 4.10 ERA, 96.2 IP, 109 H, 23 BB, 88 K at complex-level AZL, Low-A Clinton and High-A Bakersfield
Future Tools: 60 fastball, 55 change, 55 command
Role: 45—No. 5 starter

There weren’t many pleasant surprises for the Mariners in 2015, but Yarbrough qualifies. He isn’t overpowering, but he’ll throw his two- and four-seam fastballs for strikes with downhill plane, and he’ll occasionally touch the mid-90s. For the most part, he keeps that same plane and arm speed when throwing his change, and there’s just enough movement to call it an above-average offering.

Those two pitches would make Yarbrough a mid-rotation starter if had could spin a competent breaking ball. Unfortunately, Yarbrough can’t spin a competent breaking ball, at least not consistently. He locates his curveball for strikes—as he does with his other offerings—but it’s often slurvy and hangs up in the zone.

Yarbrough has a chance to start because he repeats his delivery well and throws three pitches for strikes, but expecting anything more than a fifth starter is expecting an awful lot. Not great when that’s your fifth-best prospect, is it?

Bret Sayre's Fantasy Take: Well, even bad starters get a bump in Safeco, but outside of deep leagues and AL-only formats, this just isn’t a name you should have much interest in. I mean, how much value did Mike Montgomery have in your league this year?

Major league ETA: 2017

6. Luis Liberato, OF
DOB: 12/18/1995
Height/Weight: 6’1” 175 lbs.
Bats/Throws: L/L
Drafted/Acquired/Bonus: Signed December 2012 out of the Dominican Republic for $140,000
Previous Ranking(s): Unranked
2015 Stats: .231/.308/.403, 5 HR, 11 SB in 257 PA at short-season Everett, Low-A Clinton and Double-A Jackson
Future Tools: 55 run, 55 arm, 50-plus hit
OFP: 45—Fringe-average regular corner/fourth outfielder

Like with Gohara, the Mariners have been patient with Liberato since signing him three winters ago. It looks like the slow 'n’ low approach is beginning to pay off. He possesses above-average bat speed, shows a willingness to go the other way, and isn’t allergic to walks. He can get tied up with high, inside heat, and secondary offerings give him trouble, but he’s a hard worker who has put in the effort to correct these deficiencies. There’s also sneaky pop in his bat, and while he’s not going to be a big power threat, 10-15-homer seasons at his peak aren’t out of the question.

Liberato has enough speed to play center, but defensively he profiles best in a corner, and his strong throwing arm fits well in right field. Ideally this is a Stan Javier type who plays all three outfield positions as a fourth outfielder. But if there’s a regular in this system who doesn’t play on the infield dirt, it’s Liberato.

Bret Sayre's Fantasy Take: With some speed, a little pop and the potential to hit for a decent average, Liberato could be a reasonable OF4 if everything clicks at the plate. Shallow mixed leaguers can move on, but if Ender Inciarte with less speed sounds appealing to you, invest away.

Major league ETA: 2018

7. Drew Jackson, SS
DOB: 07/28/1993
Height/Weight: 6’2” 195 lbs.
Bats/Throws: R/R
Drafted/Acquired/Bonus: Drafted in the fifth round of the 2015 MLB Draft, Stanford University; signed for $335,400
Previous Ranking(s): Unranked
2015 Stats: .358/.432/.447, 2 HR, 47 SB in 266 PA at short-season Everett
Future Tools: 70 arm, 60 speed, 55 glove
Role: 45—fringe-average shortstop/utility infielder

If you like your shortstops fast and with arms that need to be checked in at the airport, Jackson is your kind of guy. He’s an excellent athlete who makes everything look easy. His fluid actions in the field, along with his plus speed and plus-plus arm, make him as close to a lock to stick at shortstop as anyone.

Jackson destroyed short-season pitching, and his raw speed couples with an advanced ability to read pitchers to make him a major threat on the bases. But when you actually see the guy swing, it’s hard to take the numbers seriously. He’s short to the ball, but it’s mostly arms without much weight transfer, and like many Stanford hitters he doesn’t often pull the ball with authority. He is a smart, selective hitter who draws walks, but as a 45-hit, 30-power guy, it’s tough to imagine he’ll give you enough offense to play every day. Since putting in contacts he’s looked much more offensively-inclined, and should he hit at the higher levels in 2016, we reserve the right to change our opinion.

Bret Sayre's Fantasy Take: Those stat line scouters in your league will get plenty excited about Jackson, but even the skeptics shouldn’t overlook him. Sure, he’s not going to be the next Jose Reyes, but the speed and approach (even without much else) can lead to plenty of fantasy value. He’s a ways away and has plenty of hurdles to clear, but he’s played his way into the third round dynasty draft discussion this year.

Major league ETA: 2018

8. Boog Powell, OF
DOB: 07/30/1993
Height/Weight: 5’10” 180 lbs.
Bats/Throws: L/L
Drafted/Acquired/Bonus: Drafted in the 20th round of the 2012 MLB Draft by Oakland (Orange Coast College), signed for $1,000; traded to Seattle by Tampa Bay in six-player Brad Miller deal.
Previous Ranking(s): Unranked
2015 Stats: .295/.385/.392, 3 HR, 18 SB in 522 PA at Double-A Montgomery and Triple-A Durham
Future Tools: 60 speed, 55 hit
Role: 45—Fringe regular/fourth outfielder

No relation. Now that we have that out of the way, we can talk about this Powell, who offers the highest floor of any position player in the system. He sprays line drives to every part of the field from a short, compact swing, and while the walks aren’t likely to carry over to the major leagues, he’s shown outstanding patience at the plate at every level. Alas, his lack of strength and swing plane means there’s not much pop here. He has the speed to be a 20-plus stolen base player, but he doesn’t always get great jumps, and that has led to inefficient success rates in each of the past two seasons.. His lack of arm strength limits him to center or left field, while his lack of elite range makes him better in a corner than in the middle of the outfield.

One crosschecker I spoke with called Powell a “poor man’s Brett Gardner,” and while that’s not the sexiest profile, it does make him a solid fourth outfielder—possibly one who gives you 500 plate appearances of average offense if everything breaks right.

Bret Sayre's Fantasy Take: Why a player named Herschel Mack Powell would go by Boog, I’ll never understand (not because there’s no reason for the nickname, but because it’s clearly not necessary), and investing in Powell in mixed leagues is an equivalently head-scratching item. He could be an interesting reserve pick in AL-only formats this year, but that’s about it.

Major league ETA:

9. Tyler O'Neill, OF
DOB: 06/22/1995
Height/Weight: 5’11” 210 lbs.
Bats/Throws: R/R
Drafted/Acquired/Bonus: Drafted in the third round of the 2013 MLB draft, Garibaldi SS (Maple Ridge, BC); signed for $650,000
Previous Ranking(s): Unranked
2015 Stats: .260/.316/.558, 32 HR, 16 SB in 449 PA at High-A Bakersfield
Future Tools: 55 power
Role: 45—Fringe-average regular in right field

O’Neill is the son of a former bodybuilder and he’s built more like a middle linebacker than a typical outfielder. It shouldn’t surprise anybody that such a build produces plus raw power on pure strength alone, but he has also improved his hip rotation. Pair that with a step forward in his ability to transfer weight, and that raw power begins to translate more often in games. He’s extremely aggressive at the plate, and while he has the extension and plane to hit for average, he doesn’t have the approach to grade his future hit tool above fringe-average at this point. He’s more of a detriment than an asset with the glove, as he doesn’t take good routes, thereby undermining his athleticism and range.

O’Neill best projects as a lefty-basher who can give you pop off the bench. If the approach improves, there’s a non-zero chance he plays every day.

Bret Sayre's Fantasy Take: In dynasty leagues, we have a little more leeway to invest in the types of profiles that probably won’t work out but could be boons if they do. O’Neill falls squarely in that bucket, but even that leeway shouldn’t make fantasy owners view him as a top-200 prospect yet. If he does it in Double-A, then we’ll talk.

Major league ETA: 2017

10. Nick Neidert, RHP
DOB: 11/20/1996
Height/Weight: 6’1” 180 lbs.
Bats/Throws: R/R
Drafted/Acquired: Drafted 60th overall in the 2015 MLB Draft Peachtree HS (Peachtree, GA); signed for $1.2 million
Previous Ranking(s): No. 56 in Top 125 MLB Draft prospects
2015 Stats: 1.53 ERA, 35.1 IP, 25 H, 9 BB, 23 K at Arizona Instructional League
Future Tools: 60 fastball, 50-plus curve
Role: 45—Back-end starter

Neidert could have been a first-round pick if the draft had been held in the spring, but elbow tendinitis caused him to struggle and miss time. When he’s right, he’ll show a low-90s four-seam fastball that touches 96, albeit without much plane, and with a tendency to flatten as the velocity ticks up. He’ll also show an above-average curveball and an average change, though at this point neither pitch offers any reliability in movement or location. The delivery is clean, so as he gains more feel for his arsenal there’s a chance he develops into a solid mid-rotation starter. There’s a long way to go, however, and he’s just as likely to end up a middle reliever as he is a member of a rotation.

Bret Sayre's Fantasy Take: Nope.

Major league ETA: 2019

Five who are just interesting:

Austin Wilson, OF – I thought Austin Wilson was the steal of the 2013 draft with the 49th pick, and, well, it hasn’t worked out. There are still two 60 tools at his disposal, thanks to his impressive raw power and his strong throwing arm, but there’s also a present-30 hit tool, and he hasn’t looked like much more than a 45 outfielder at this point, either. In a system this weak, he’d probably make a top 15; yet he’s closer to a non-prospect than he is a potential regular.

Nick Wells, LHP – Wells was acquired along with Jacob Brentz—who is another interesting arm—in the Mark Lowe trade, and he very nearly made the top 10. His 6-foot-5, 185-pound frame oozes projection, as he touches 93 already with his four-seamer and complements it with an above-average curveball. All that’s missing right now is a consistent changeup for him to become a solid mid-rotation starter, and considering he won’t turn 20 until February, there’s plenty of time. It’s all very raw, but raw isn’t so bad. It’s better than spoiled.

Brayan Hernandez, OF – I received an array of reports on Hernandez coming into the international signing period, with some saying he was the best outfielder in the class and others claiming he was one of the more overrated. The Mariners obviously sided with the former, as they gave him $1.85 million. He’s a line-drive hitter with above-average bat speed, and his relatively advanced approach pairs with nominally above-average speed to make him a potential leadoff hitter. He’s a solid if not spectacular defender in center, and he has enough arm strength to move over to right. Like any 18-year-old international free agent, there’s a boatload of volatility here, but if Hernandez impresses in his stateside debut, he’ll jump up this list.

Ian Miller, OF – Miller wasn’t on many radars coming into the 2015 season, but the man I call Teen Archer quickly changed that with a decent campaign. He’s a plus-plus runner (as evidenced by his 50 stolen bases), and he uses that speed to get great jumps in center field, rating plus there as well. He’s also a 20 power hitter with a swing that has a lot of moving parts, and his hit and power tools don’t add up to his run grade. Still, you’re an interesting prospect anytime you can create on the bases and go get it with the glove.

Dan Altavilla, RHP – A year after Altavilla was the Division II pitcher of the year at Mercyhurst University, Seattle challenged him with a promotion to Bakersfield. While there were some bumps in the road, the season can be deemed an overall success. He has feel for missing bats with a four-seam fastball, but at just 5-foot-11 the right-hander struggles to get much plane on the pitch.. He also features a hard, tilting slider that grades solid-average, and his change is an improving fringe-average offering that should grade higher as he gains feel. Despite the lack of plane, he does a good job keeping the ball below the knees (only 11 homers in 148 innings in the Cal League), and the command should be good enough to start. Seattle should fast-track his arm via the bullpen, as his fastball has been up to 97 in short spurts, which could make him a set-up man or closer.

Top 10 Talents 25 And Under (born 4/1/90 or later)

1. Taijuan Walker
2. Ketel Marte
3. Alex Jackson
4. Edwin Diaz
5. Luiz Gohara
6. D.J. Peterson
7. Ryan Yarbrough
8. Luis Liberato
9. ​Drew Jackson
10. Boog Powell

Reviewing the players eligible for the "Top 25 and Under" list reveals just how old the Mariners are. Only three players on the 40-man roster are eligible for this list: Walker, Marte and shortstop Luis Sardinas. Just a handful of other players were born in the nineties, and with apologies to Chris Taylor, Tony Zych, Mayckol Guaipe and Steve Baron, most of them project as fringe contributors. Combined with the state of the farm system, it’s clear that the Mariners have one of the shallowest collections of young talent in the league.

That’s to take nothing away from the top two names on this list. Reasonable people could argue that Walker and Marte should be flipped, but either way, both are pieces that this team can build around.

Walker took a beating in the season’s first two months, but his performance from late May through the end of the year resembled the production you can expect from a No. 3 starter. He fell behind in the count way too often early on, but quickly righted the ship: after walking 23 hitters in his first nine starts, he allowed just 17 in his final 20 outings. He also began using his fastball-changeup combination to better effect, and his mediocre slider improved over the course of the year. He’s not an ace—neither the slider nor curve will miss enough bats—but it’s safe to project him as a reliable mid-rotation starter and possibly a bit more if his command improves.

Marte was hot from the moment he arrived in Seattle. Starting at shortstop and thrust into the leadoff spot, Marte turned in a .283/.351/.402 line over the season’s final two months. While his hitting mechanics are unconventional—he lifts his hands higher than most players and his bat doesn’t stay in the zone for long—they work for him, and the switch-hitter will rope plenty of line drives from both sides of the plate. It’s less clear whether he can maintain a similar OBP going forward. Marte posted the best walk rate of his life in the big leagues last year, and it’s probably best to project a bit of regression in that category. Still, as a big league shortstop with a decent stick and enough range to compensate for a below average arm for the position, he’ll be a valuable asset in the lineup for years to come.

Sardinas once appeared on BP’s top 101 prospect list, but at 22, he appears more likely to have a career as a good utility man than a big league regular. His contact skills haven’t translated at the big league level yet, and his lack of strength means he’s a singles hitter when he does connect. He can pick it at short though, and he’ll have every chance to win a job backing up Marte this spring.

Mike Zunino is also worthy of a mention here. He’s ineligible for this list by a matter of days, and while his offensive performance to date suggests that he’s nothing more than a backup catcher at this point, he has the talent to contribute more. Unjustifiably rushed to the majors in 2013, Zunino will return to Triple-A this season. It’s a developmentally appropriate level for a player who regularly misses hittable offerings and expands the zone too easily. If Zunino can learn to either control the zone better or punish mistakes more often, he could still be a second division regular. — Brendan Gawlowski

The Executives

General Manager: Jerry Dipoto
Director, Amateur Scouting: Tom McNamara
Director, Player Development: Andy McKay

The Mariners gave Jack Zduriencik every chance to succeed, and succeed he did not. He also left this farm system in shambles, and Dipoto will have plenty of work to do to reestablish this group. He’s a sharp guy with a strong scouting background in Boston, Colorado, and Arizona, so no one should be surprised if he does just that.

One thing that did surprise many was the decision to keep McNamara on board. He’s by no means a laughingstock, or anything close, but he’s also been in charge of some lethargic draft classes. The thought process may be that he was hamstrung by Zduriencik, but it was widely assumed that when Dipoto was hired, he’d bring in his own director. (That might have changed when Dipoto made his former director the team’s major-league manager.) We’ll see how long a leash McNamara has.

As poor as some of the drafts have gone, the player development has been just as unimpressive. Prospect after prospect has entered this system and regressed in approach or command, and it’ll be up to McKay—who specializes in optimizing mental performance—to turn that around. He received rave reviews for his work as the Peak Performance Coordinator with Colorado, and it’ll be up to him and his staff to figure out how to get Jackson, Peterson, Wilson, and O’Neill to start showing more selectivity at the plate. If he can, you’ll start seeing a lot more teams go this route with their player development leads.