Everett AquaSox

SeattleClubhouse Top-50: Seattle Mariners' prospects No. 10 through 6

Our penultimate report in our 2016 Top-50 prospects in the Seattle Mariners’ organization. Each player review is complete with scouting notes and quotes from various baseball sources from inside and outside of the M’s organization. Our initial list of close to 100 names was trimmed to the final 50 with that help, but the final rankings are the opinion of SeattleClubhouse and don’t necessary reflect the views which we take into consideration while making the final cut down.

Here at SeattleClubhouse, our primary goal in covering the Seattle Mariners is to give our readers exclusive, in-depth information on players in the organization from the foreign Rookie League teams all the way to the Major Leagues. We do this by looking beyond just statistics and typical web resources and using direct input from the Mariners' staff -- including Jeff Kingston, Andy McKay, Tim Allison, Tom McNamara, Tim Kissner and others -- and other respected baseball contacts from outside of the organization to help develop our unique set of rankings. SeattleClubhouse's personal taste and scoring plays into the determination of where the prospects land on the list, too; that scoring system is a combination of potential ceiling, perceived likelihood of reaching that ceiling, the most probable outcome for the player and their proximity to cracking the 25-man roster, but also age, level, tools, etc. are weighted. The aim is to give the readers rundowns on the names in the Seattle system that are worth tracking for the coming season and maybe even pinning future MLB hopes on. 

We do updates on a smaller scale throughout the year, but just as with every pre-season list, this pre-2016 countdown is 50 deep. The landscape of the organization has definitely changed since our last report, even in the Top-5, so this extended breakdown will be much different as it is a true fresh look at the organization as it now exists, with completely up to date late- or post-season input. The reports will be thorough for all players covered, but they'll get more so as we climb towards the top of the heap. And while four of the ten pieces will be free for anyone who visits the site, the other six will be subscriber only.

As you will see during this countdown, many of the higher-ceiling prospects in the Mariners’ system are on the younger side, residing in the lower levels of the minor leagues. So while the system isn’t as bereft of talent as the common narrative seems to be, there aren’t many MLB-ready prospects knocking on the door, and that is primarily what leads to this generally being considered a bottom-third system in baseball.

Each player we cover this year will be presented with a photo (when available) and bio info as well as the level at which they ended during the 2015 regular season. Players who have finished their age-26 season and those who have exhausted their Rookie status per Major League guidelines are not eligible for consideration. Discussion in the forums is welcome, but until the entire Top-50 is released for all (after the individual pieces are finished), please keep discussion on the information from subscriber pieces in the subscriber forums.

Previous Reports:

Nos. 50 through 46

Nos. 45 through 41

Nos. 40 through 36

Nos. 35 through 31

Nos. 30 through 26 (SUBSCRIBER ONLY)

Nos. 25 through 21 (SUBSCRIBER ONLY)

Nos. 20 through 16 (SUBSCRIBER ONLY)

Nos. 15 through 11 (SUBSCRIBER ONLY)

And now we are cracking the lid on the Top-10 here with our second to last piece of this annual pre-season ranking, covering prospects number 10 through 6 in our sixth annual Top-50 countdown with these five reports.

Seattle Mariners

10. Luis Liberato – OF, 6’1”, 175, SS, 12/18/95, L/L

233 52 8 3 2 17 23 50 .255 .338 .353 .691
210 37 6 3 2 14 29 47 .211 .325 .314 .640
257 51 11 6 5 31 26 59 .231 .308 .403 .711
700 140 25 12 9 62 78 156 .233 .323 .360 .683

Liberato, who was signed out of the Dominican in December of 2012 for a reported low six figure deal, wasn’t truly on the prospect radar when 2015 opened. After struggling a bit at two higher levels to open the year, he landed in Everett and got off to a blazing start for the AquaSox, ranking among the leaders in several offensive categories after the NWL's first few weeks. He was given the Player of the Week Award for the Northwest league for his work June 22nd through June 28th (.458, 2 2B, 2 3B, HR, 2 SB) and represents a threat in all aspects of the game. Gifted athletically with a bevvy of tools at his disposal, Liberato played all three outfield spots and ended the year tied for third on the club in homers and walks and tied for fifth on the club in steals while his .453 SLG ranked second on the club and ninth in the league overall. Luis was recognized by the organization as the standout defensive outfielder for Everett after the season, which is saying something on a club that had Braden Bishop roaming the outfield.

One Everett staffer said of Luis, "Good foot speed, bat speed, plate discipline, and more than a modicum of pop. He was nicked up a few times this year but still wound up having a good season." He wrapped up his take on the outfielder saying, "covers all five tools rather nicely." While his approach at the plate is raw and that helped lead to some wild swings in production -- his AVG by month went .133, .302, .206, .254, speaking to those inconsistencies --  Luis handled himself reasonably well against left-handed pitchers and he ended his year with four multi-hit efforts in his last 12 games. The strikeout rate of 23.0% is high, but the ability to do damage with the bat is real. And although he would sell out for power a bit at times, which led to some of the swing-and-miss issues, Liberato hit a ground ball more than twice as often as he hit a fly ball this year.


Liberato did show patience at the plate at times, displaying a willingness to hit deep in a count, but the 'plan' part of his approach didn't seem fully developed even if the ability to wait for a good pitch was present -- being patient doesn't just mean taking pitches. Still, the willingnes to work a walk is in him, and that is something that the new front office has targeted as a trait they'd like to see in their players. The Mariners do have several talented outfielders in their low minors, but Liberato is one of the most exciting in terms of combination of tools, with speed, power, the ability to play all three outfield spots and the ability to throw. 

Again, he can sell out for power at times, but Liberato has good strength and loft to his swing, showing that natural power is in there, even with his currently slight frame. He's a plus runner with a plus arm, although the arm can be wild at times. With his bat speed and more exposure to pro pitching, Luis could have the ability to hit for a solid average, too. It does figure that he'll grow off of center and settle into an outfield corner, and depending on how much he grows, his speed could go down to average, too. But Liberato's potential with the bat and underlying athleticism should keep him at least as a strong corner guy. Having already had a taste of Clinton, Liberato figures to head back there to open 2016 in what could be a very good and productive outfield for the LumberKings.

TOP TRAIT(S): Bat speed, range, arm, speed, power potential

Durham Bulls

9. Boog Powell – OF, 5’10”, 185, AAA (TB), 1/14/93, L/L

130 34 1 0 0 13 15 9 .306 .383 .315 .698
245 60 7 3 0 14 26 34 .283 .364 .344 .708
380 108 10 5 3 28 61 53 .343 .451 .435 .886
522 131 16 9 3 40 61 79 .295 .385 .392 .777
1277 333 34 17 6 95 163 175 .308 .401 .387 .788

Powell, acquired from Tampa Bay in the first trade that GM Jerry Dipoto orchestrated for the club back at the beginning of November, is probably the prospect in Seattle's system that is closest to contributing to the big league club at this point. While he was a good player in Oakland's system and had a very strong 2014 across two levels for the A's, it was after his trade to Tampa Bay prior to 2015 where Powell really took off. Boog -- who's given name is Herschel Mack Powell, and who has no relation to the former Orioles' star -- hit a combined .295/.385/.392 while climbing two levels for the second consecutive season and setting personal high marks in a number of categories, including hits, runs, doubles, triples, RBI, steals and total bases. And those were the minors' two highest levels. The left-handed hitting outfielder also tied his marks from 2014 in BB (61) and HR (3) while setting a new personal best in outfield assists with 11. He was a Southern League All-Star and was among the leaders there in a number of categories prior to his promotion to Triple-A.

While a lot of his slugging numbers the past couple of seasons have been tied to his triples total more than anything else, Powell has shown an ability to get his bat on the ball and do damage at the plate despite probably being a 30 in the power department. He can get by with that as he puts the ball in play, hits well late in counts and runs well enough to beat out infield hits. His 12.8% walk rate for his minor league career (13.5% the last two seasons) is incredibly strong, as is his low 13.7% career MiLB strikeout rate. As you can see in the video below, his swing is geared for contact, with a short, compact, level stroke. That stroke produces line drives that he is comfortable spraying all over the field because -- as the M's like to say about their young players -- Boog knows who he is. He is a singles hitter that will run some balls into extra bases when they're down the line or in the gaps.

Powell is a 'gamer' and will sell out on defense and on the basepaths. He hasn't yet been successful as a pro basestealer -- just 53 for 90 overall, and 18 for 32 in 2015 -- but he is an above average runner. That speed and hustle gives him the ability to profile as a future centerfielder in the big leagues...if the offense can keep up. A lot of the value he can provide on offense will come from his ability to draw walks. Powell was suspended for 50 games during the 2014 season for violating the Minor League Drug Prevention and Treatment Program.

While he only has 56 games under his belt at the Triple-A level, Powell looked like he could be Seattle's MLB starter in center until the club acquired Leonys Martin from Texas. While that means he'll likely start the season in Triple-A Tacoma or on the big league bench, Jerry Dipoto has reiterated that Powell was acquired because he is the type of player that this organization and it's new front office want. Powell figures to see some time in Seattle this year regardless of where he starts, and his speed, OBP abilities, defensive abilities and catchy nickname figure to make him a fan favorite quickly.

TOP TRAIT(S): Plate discipline, speed, defense

8. Nick Neidert – RHP, 6’1”, 180, AZL, 11/20/96, R/R

1.53 11 35.1 9 23 0.962 6.4 0.3 2.3 5.9 2.56

Seattle's top pick in the 2015 Draft out of Peachtree Ridge high school in Suwanee, Georgia, Neidert made 11 starts in the AZL for Seattle, going winless but allowing earned runs in only four of his 11 outings while holding opposing hitters to a .198 average and .514 OPS while pitching the third most innings on the little M's staff, which was a very strong debut overall. He was the pitching "C the Z" winner for Peoria in August and pitched four games of four innings or more without allowing an earned run. Right-handed batters touched Nick for just a .175/.224/.213 slash, and while he managed just 23 strikeouts in his 35 1/3 innings of work, only one starter in the AZL threw more innings and allowed fewer hits-per-nine than did the young Seattle right-hander (6.4). Nick, who pitched all season at age 18, gave up just five extra base hits to 135 batters faced (3.7%) and had a 2.55 groundout-to-airout ratio.


In his senior season leading up to the draft, Neidert had some arm fatigue that later was diagnosed as elbow tendinitis which caused him to miss some time, but seeing regular work and increasing innings as the AZL season went on, he showed no signs of arm issues. He doesn't have a big frame, is only 6-foot-1 and throws from a mid- to low-three-quarters arm slot, but he commands the lower half of the strikezone from that release point, gets good movement on his fastball and battles on the hill. "He's a really intelligent player and a bulldog on the mound," said one former M's staffer about Neidert last fall. 

Smallish right-handers don't usually get a lot of play from the prospect crowd, especially if they don't have top-end velocity or plus breaking balls. But Neidert has had a lot of 'Tim Hudson' comps thrown his way. Maybe that is just lazy scouting because of the body, but maybe there is something there based on repertoire more than stature. If that plays out, certainly the Mariners would consider themselves extremely fortunate.

Nick works primarily fastball-changeup and uses his slurvy breaking ball as his third offering. The fastball was regularly 90-92 this past summer in Arizona but he touched 96 with it in the spring, and with his release point the pitch does have good movement. His changeup is a plus pitch now, and the offering has good fade on it and consistent arm speed. Neidert may move to a slider (or even add a cut fastball) in the coming seasons to get a more consistent offering as his third pitch. He doesn't have big shoulders or hips and doesn't figure to get up much beyond 200 pounds even as he matures, but the club is confident that he is a starter. 2016 will likely see him in Everett.

TOP TRAIT(S): Athleticism, command, arm speed, changeup

Seattle Mariners

7. Austin Wilson – OF, 6’4”, 249, A+, 2/7/92, R/R

226 49 11 3 6 27 17 42 .241 .319 .414 .732
308 81 18 4 13 55 27 67 .301 .384 .543 .927
442 91 17 2 10 48 31 115 .239 .342 .374 .715
976 221 46 9 29 130 75 224 .259 .350 .437 .786

Wilson was a very highly regarded prospect coming out of Harvard-Westlake high school in 2010 and coming out of Stanford in 2013, when Seattle selected him in the 2nd round. After a very strong (albeit injury-riddled) 2014, Wilson stepped into the offensive-friendly environment of the California League in 2015....and fell a bit flat. His big power didn't play hardly at all early in the season, and by the time the offense showed up in the last week of July, his season numbers were already pretty buried. But Austin did hit .326/.424/.541 over the year's final 36 games, banging out 18 extra base hits in 36 games and picking up nearly 150 points on his OPS. Number 3 on our countdown a year ago and 10th on the list the year before, Wilson hasn't climbed despite the system weakening dramatically because he hasn't taken that next step yet. Playing in High-A as a 23 year old in 2015, Wilson still struck out a lot (26.0%) and had that long stretch of games that were really a struggle.

Bako's Dan Besbris watched Wilson every day in 2015, and he said that, "Wilson struggled with the inside fastball. That was a spot that teams attacked relentlessly. As the year went on, he began to get started a bit earlier, and also learned to take one for the team, often getting hit by a pitch when the opposing hurler missed off the plate." Indeed, Wilson's 29 HBPs were the second highest number in the minors and he was hit twice in a game three times in a 20 day stretch late in the year. So even though he only drew 31 walks, Wilson had better than a .100 gap between his average and on-base percentage.

He is more than just a power hitter, though. Wilson was recognized by the organization as the standout defensive outfield for Bakersfield following the season, and considering his size and some of the other players on the roster, that is definitely an accomplishment worth acknowledging. And while the power is Wilson's biggest obvious tool, it remains more of a tease than a known commodity. "Between he and [Tyler] O'Neill, batting practice home runs are a thing of dreams," Besbris said. But that big time power potential in BP has yielded just 29 home runs in 976 minor league plate appearances in games to date for Wilson. The 20 year old O'Neill hit 32 in 449 PAs in 2015 alone for Bakersfield.


Wilson has good bat speed and a good idea of what he wants to do at the plate. That said, he has been beat often by velocity up out of the zone and breaking balls down or away out of the zone. His plus power plays to all fields, as the spray chart of his minor league home runs above shows, but Wilson tended to sell out for pull power with Bakersfield early while he was struggling. He runs well for a big guy, too, and is more than just an arm in right field, showing true outfield instincts and ranging for balls both towards center and towards the line. He moves on the bases well, too, and swiped eight bases for the Blaze this past season. Wilson figures to get a shot at Double-A in 2016, and that will be a tough jump for him. But if he can avoid the long slumps and trust his power to play to all fields a bit more, he could make a big jump in the coming season.

TOP TRAIT(S): Power, arm, size

Everett AquaSox

6. Drew Jackson – SS, 6’2”, 195, SS, 7/28/93, R/R

266 81 12 1 2 26 30 35 .358 .432 .447 .879

Jackson wasn't a top prospect coming out of Stanford despite a strong junior season, but after being Seattle's 5th round selection in June, he showed up in Everett and turned in an electric first year as a pro. The shortstop lead the Northwest League in hitting, easily led it in steals (47), ranked fourth in total bases (101), turned in a 20-game hitting streak and quite deservedly won the MVP.  That steal total was the 14th highest number in the minors, and all but one of the players ahead of him (Atlanta prospect Randy Ventura) played in at least 102 games. Also, no one who got 40-plus bags in the minors bested Jackson's steal success rate of 92.2%. Drew also led the club in walks (30) and was one of the harder players to strike out in the league, with a 13.2% rate. He was the "C the Z" award winner for hitting for Everett in July and flirted with the league record and a .400 average late into the year -- he was hitting .397 with eight games left in the season before finishing 4-for-32 -- for the Frogs. He collected multi-hit games in 25 of the 59 games he played, had a 22-game errorless streak at shortstop and stole at least one base in six straight games twice during the season. Originally drafted in the 37th round by the Giants out of high school, he's the younger brother of former top prospect Brett Jackson.

Putting all of those accomplishments together, it is easy to see where all of the accolades come from. On top of the MVP, Baseball America ranked him as the 5th-best prospect in the NWL after the season, and he is pretty much a consensus as one of Seattle's top ten prospects now. "I can’t remember seeing a better all-around player in this league," said a long time member of Everett's staff, continuing "he oozes talent, skill and athleticism. The defense is like [former Top-50 prospect] Jack Reinheimer with more range and a much better arm. Depending upon how he comes out in Spring Training, I could see him getting to Double-A before the end of 2016."

Jackson's best tools exist on the defensive side of things and he wasn't someone who dominated in college, so how did he turn in the best offensive season in the system? Implementing speed into his game was a huge boost, for one. Drew stole just 13 bases in his 120 game college career. The college game is different, obviously, and as Jackson told the Everett Herald in July, "It's been nice to work with (Sox batting coach) Brian Hunter and the other coaches on stealing. I'm not really realizing how much I'm stealing. It's basically like I'm working on it every day, trying to get better jumps, and it's paying off." But that speed also came into play because of how Jackson hit the ball -- he almost never hit the ball in the air (see the below chart). He didn't show a ton of power despite great contact numbers, and he won't be a home run threat, but Jackson has good size and strength, and if the fly ball rate were to increase, it is reasonable to expect that he could reach a few more gaps and add to his extra base totals.


His arm may be the single best tool in the entire organization -- a true 70 weapon that should enable Drew to stick at shortstop long term -- but Jackson's big totals in the running game are no fluke, either. He's at least a plus runner who gets great jumps and reads the pitcher and the ball well (stealing bases and advancing on batted balls), showing plus overall athleticism. He has the hands, lateral range and instincts for shortstop, too, and even though his error total wasn't great, Jackson showed as a plus defensive asset for Everett overall. His patience and discipline at the plate are plus, and as stated before he has good contact skills. The only short tool in his game right now is really power, and -- again -- Jackson has good size and strength. A few tweaks to his swing could yield great results if they take. I wouldn't be surprised if Jackson gets that chance in Bakersfield in 2016, but he may start in Clinton.

TOP TRAIT(S): Arm, speed, plate discipline

That wraps up our second to last report, going in-depth on prospects No. 10 through 6 in the Seattle Mariners' organization. Next Monday we will wrap this annual ranking up with the five very best prospects in Seattle's system. Be sure to check in for that, and for all of our reports throughout the year.

Looking for more Mariners news, articles and player interviews? Want to keep up with which prospects are hot and cold for the M's? "Like" SeattleClubhouse on Facebook and follow SeattleClubhouse site Editor Rick Randall on Twitter at @randallball.

Seattle Clubhouse Top Stories