Seattle Mariners Top 20 2016 PRE-SEASON prospects in review

Moving forward with our reviews of the pre-season prospect lists, we turn our attention to the Seattle Mariners.

Remember, this is the PRE-SEASON List.

This is not a new list.

These are pre-season grades.

Discuss current Mariners events in the comments section.

This list was originally published March 13, 2016

1) Edwin Diaz, RHP, Grade B: Age 22 this is what I wrote last spring: fastball at 93-97 with peaks at 98, slider and change-up have steadily improved, both solid-average at least and slider may be plus; control good, potential mid-rotation starter. Do not underestimate him. As you know, Mariners moved him to pen and he blossomed into MLB force immediately, 2.15 ERA with 69/13 K/BB in 38 innings, 11 saves; this isn't the role I thought he'd have but damn he's good.

2) Alex Jackson, OF, Grade B/B-: Age 20, first round pick in 2014, hitting .250/.338/.422 with 11 homers, 32 walks, 96 strikeouts in 308 at-bats in Low-A; not a terrible season and better than 2015 but not what the Mariners thought they were drafting; still young enough to improve. 

3) Drew Jackson, SS, Grade B-/B: Age 23, fifth round pick out of Stanford had stunning debut in 2015, not as good this year at .263/.336/.353 in High-A, 13 steals, 45 walks, 94 strikeouts in 487 at-bats; has played well defensively but bats hasn't lived up to what he did in the Northwest League; can still improve of course.

4) Tyler O’Neill, OF, Grade B-/B: Age 21, excellent season in Double-A at .300/.381/.522 with 23 homers, 59 walks, 135 strikeouts in 464 at-bats; bat speed and power are big plusses but contact could be troublesome at higher levels, which could impair batting average/OBP; plate discipline has improved this season.

5) Nick Neidert, RHP, Grade B-: Age 19, second round pick in 2015 from high school in Georgia; 2.42 ERA in 78 innings in Low-A, 61/12 K/BB, 64 hits; very low walk rate with good reports on secondary pitches, carefully limited workload but overall a success.

6) Andrew Moore, RHP, Grade C+/B-: Impressive season in High-A and Double-A, 12-2 in 26 starts with 2.38 ERA, 125/28 K/BB in 155 innings, 139 hits, extremely efficient strike-thrower and an excellent campaign from 2015 comp round pick from Oregon State. Could be ready next year.

7) Luiz Gohara, LHP, Grade C+: Massive improvement at age 20, 1.95 ERA in 65 innings with 75/19 K/BB between short-season Northwest League and Low-A; looks like he's putting everything together with drastic sharpening of command, secondary pitches, and more consistent velocity. Stock up.

8) Boog Powell, OF, Grade C+: Hitting .270/.326/.359 through 248 at-bats in Triple-A; suspended 80 games in late June for PED use. Skills/tools to be a fourth outfielder assuming he is clean.

9) Ryan Yarbrough, LHP, Grade C+: Sharp season in Double-A with 12-4, 2.92 record in 24 starts, 98/31 K/BB, 108 hits; went on disabled list August 22nd with undisclosed injury; on verge of promotion before getting hurt.

10) Nick Wells, LHP, Grade C+: Age 20, ultra-projection lefty (6-5, 185) acquired from Blue Jays in Mark Lowe trade,  a rather blah season in Low-A with 5.30 ERA in 75 innings, 52/36 K/BB, 86 hits; Midwest League reports emphasize projectability and potential as well as current rawness.

11) Tony Zych, RHP, Grade C+: Opened season in Mariners bullpen but has spent most of the year on disabled list with rotator cuff tendinitis; just back in action now; still expect him to be an effective reliever if healthy.

12) Dan Altavilla, RHP, Grade C+: Fine season in Double-A, 1.91 ERA in 57 innings with 65/22 K/BB, 16 saves, just 40 hits allowed; still some command issues but should be ready for bullpen trial next year and has nice middle relief potential.

13) Austin Wilson, OF, Grade C+: Age 24, disappointing season repeating High-A at .217/.330/.358, 11 homers, 45 walks, 148 strikeouts in 341 at-bats; you can have all the raw power in the world but if you can't make contact. . .

14) Braden Bishop, OF, Grade C+: Age 23, third round pick from University of Washington in 2015, hitting .274/.341/.321 in 380 at-bats between Low-A and High-A, two homers, 34 walks, 78 strikeouts, eight steals; fine defender but not doing enough with the bat to stand out at this point.

15) Jio Orozco, RHP, Grade C+: Age 19, 14^th round pick from Arizona high school in 2015; repeating rookie ball with 4.53 ERA in 44 innings, 54/14 K/BB; nice component but we need to see him at higher levels.

16) Dylan Thompson, RHP, Grade C+: Age 19, fourth round pick in 2015 from high school in South Carolina, has thrown just three innings in rookie ball; like Orozco there is plenty of physical potential here but even less hard data on which to make a balanced judgment.

17) Cody Mobley, RHP, Grade C+: Age 19, eighth round pick in 2015 from high school in Indiana; part of nice group of high school arms selected in the ’15 draft by Mariners; has thrown just one inning in rookie ball. See Thompson.

18) D.J. Peterson, 1B, Grade C+: Just went on disabled list at Triple-A Tacoma; was hitting combined .264/.327/.455 with 19 homers, 38 walks, 119 strikeouts in 455 at-bats between Double-A and Triple-A; getting to his power much more often this year but batting average/OBP/contact remain highly questionable; needs to progress soon at age 24.

19) Paul Fry, LHP, Grade C+: Decent season in Triple-A, 3.19 ERA with 55/28 K/BB in 48 innings; good slider, needs better control; reverse platoon splits so not an ideal LOOGY but could be decent general reliever.

20) Luis Liberato, OF, Grade C+: Age 20, Dominican Republic signee in 2012; hitting .259/.342/.365 with 46 walks, 94 strikeouts in 359 at-bats in Low-A; has the tools to improve on this in time.

OTHERS OF NOTE: Greifer Andrade, SS; Jonathan Aro, RHP; Rayder Ascanio, INF; Jacob Brentz, LHP; Mayckol Guaipe, RHP; Guillermo Heredia, OF; Brayan Hernandez, OF; Tyler Marlette, C; Gareth Morgan, OF; Tyler Pike, LHP; Dario Pizzano, OF; Tyler Smith, SS; Christopher Torres, SS

Discuss current 2016 Mariners prospect events in the comments section.