Here’s a closer look at how the top Mariners’ 10 prospects, per Baseball America’s yearly rankings, are doing three months in.

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ANAHEIM, Calif. – The 2015 amateur draft is finished, and the bulk of those athletes selected by the Mariners are now signed and playing for lower-level minor-league affiliates in the organization. As for the current top prospects in the Mariners’ system, it hasn’t been a great start to the season for several of them.

Here’s a closer look at how the Mariners’ top 10 prospects, per Baseball America’s yearly rankings, are doing three months in.


1. Alex Jackson, OF

The Mariners’ first-round pick (No. 6 overall) from the 2014 draft struggled to start the season with Class A Clinton, hitting .157 with six doubles, no homers and 13 RBI in 28 games. Jackson had a .240 on-base percentage with a .240 slugging percentage. He had also struck out 35 times with just six walks.

The jump from the Arizona Rookie League to full-season Class A and a nagging shoulder injury that he suffered while diving for a ball in spring training were at the root of his struggles.

The Mariners decided to shut him down May 19, optioning him back to extended spring training to allow the shoulder to rest. The plan was to have him join Class A Everett once the shoulder was back to 100 percent. Jackson rehabbed and played in some extended spring-training games. When the AquaSox opened the season, he was on the roster and starting in the outfield. After going 0 for 8 in his first two games, Jackson has eight hits in his last five games and is batting .445 with two doubles and an RBI.

2. D.J. Peterson, 3B/1B

There was some thought that Peterson might be a midseason call-up to the big leagues this season and possibly the starting first baseman by the 2016 season. But that expedited road has featured a few bumps. With a logjam of first-base types at Class AAA Tacoma, Peterson returned to Class AA Jackson to start this season and isn’t doing much there. Peterson’s slash line of .208/.287/.304 is not what the Mariners expected for a second stint at AA. He has just 29 extra-base hits (13 doubles, two triples and four homers) with 64 strikeouts in 250 at-bats. Peterson is hitting just .192 with a .607 OPS with runners in scoring position.

“It’s a combination of things,” said Chris Gwynn, Mariners director of player development. “It’s the first time he’s ever really struggled. They’re pitching him away, and it’s up to him to make an adjustment. I think he’s going to come out of it.”

3. Ketel Marte, SS/2B

Despite being just 21 and in his first full season at the Class AAA level, along with lingering questions about his defensive capability at shortstop, Marte’s production at the plate was forcing the Mariners to look at him as a possible call-up.

But on May 31, Marte suffered a broken thumb sliding into second, and his chances of a call-up were put on a two-month hold. At the time of his injury, Marte had a .343/.394/.434 slash line in 51 games. The .343 batting average was second highest in the hitter-friendly Pacific Coast League. Marte also had 17 stolen bases with 18 walks and just 20 strikeouts.

The numbers were still good enough to earn him a spot on World Team at the Futures Game on July 12 as part of the All-Star festivities. Marte has begun working out at the Mariners’ complex in Arizona, and he is expected to be ready by the Futures Game.

The biggest question for Marte is his future as a shortstop. There is a thought within the organization and from opposing scouts that Marte doesn’t project as an everyday big-league shortstop. With Robinson Cano at second base for the foreseeable future, there is a chance that Marte could be moved to center field next season to capitalize on his plus speed.

4. Patrick Kivlehan, 3B/1B/OF

In his first full season at the Class AAA level, Kivlehan has already experienced the highs and lows in just 69 games. The former Rutgers football player, taken in the fourth round of the 2012 draft, has ascended through the minor leagues quickly with outstanding production at each stop. When he hit five homers and two doubles in his first 15 games, it looked like he might do the same for Class AAA Tacoma. But he struggled for a stretch. His batting average dropped to .209 with a .653 OPS and he had just two doubles and a homer in a 19-game stretch.

He’s slowly re-adjusting and starting to put up numbers. Kivlehan has only raised his average to .234, but leads the Rainiers with 13 homers and has driven in 40 runs.

5. Austin Wilson, OF

The slugging Stanford standout is struggling for Class A Bakersfield. In a league where hitters flourish, Wilson is hitting .192 with four doubles, five homers, 19 RBI and a .584 OPS in 58 games. Wilson has struck out 63 times in 203 at-bats.

6. Edwin Diaz, RHP

Diaz will be joining Marte on the World Team at the Futures Game. The hard-throwing 21-year-old is adjusting to life at the Class AA level after dominating with Class A Bakersfield. In seven starts with the Blaze, Diaz posted a 2-0 record with a 1.70 ERA and 42 strikeouts in 37 innings pitched.

He was promoted to Class AA Jackson on May 15. Diaz has been tested at the advanced level, posting a 2-5 record with a 5.48 ERA in seven starts.

7. Gabby Guerrero, OF

The Mariners traded Guerrero to the Arizona Diamondbacks as part of the six-player deal that brought Seattle designated hitter Mark Trumbo and left-handed pitcher Vidal Nuno. Guerrero was hitting .215 with 10 doubles, two homers and 15 RBI and a .567 OPS in 48 games for Class AA Jackson at the time. In 18 games with Arizona’s Class AA affiliate, Guerrero is hitting .239 with four doubles, two triples, two homers and 10 RBI.

8. Luiz Gohara, LHP

The 18-year-old lefty from Brazil is back with the AquaSox for another season. Last season, Gohara went 0-6 with an 8.20 ERA in 11 starts for Everett. In 371/3  innings pitched, he struck out 37 batters and walked 24. Blessed with a low- to mid-90s fastball, Gohara is nothing but potential. In one start for Clinton and two for Everett, Gohara is 1-0 and hasn’t allowed an earned run in 17 innings pitched with nine hits allowed, five walks and 18 strikeouts.

9. Ryan Yarbrough, LHP

The big lefty had a solid first season, posting a 1.40 ERA in 10 starts and two relief appearances last season for Class A Everett. A fourth-round pick in the 2014 draft out of Old Dominion, Yarbrough is dealing with the hitter-friendly Cal League this season. In 11 starts with Class A Bakersfield, Yarbrough has a 2-5 record with a 4.23 ERA. In 551/3 innings pitched, he’s struck out 40 batters and walked 12. He was placed on the disabled list June 4 with a groin strain and transferred to extended spring training.

10. Carson Smith, RHP

The side-armer has moved from middle reliever to set-up to de facto closer this season. Smith has appeared in 32 games and has a 1-2 record with five saves and a 1.48 ERA. He’s been Seattle’s best reliever this season, striking out 36 hitters in 301/3 innings pitched.