Pitching remains strength of a deep Seattle system

MLB Pipeline checks in from Spring Training camp, unveils team's Top 20 Prospects

Pitching remains strength of a deep Seattle system

PEORIA, Ariz. -- Robinson Cano's $240 million free-agent contract might signal otherwise, but the Mariners are committed to building from within.

Seattle graduated three premium hitting prospects to the Major Leagues last year, and Nick Franklin, Brad Miller and Mike Zunino helped the club avoid finishing last in the American League in scoring for a fifth straight time. The Mariners are counting on them and other homegrown products such as Dustin Ackley, Michael Saunders and Kyle Seager to provide enough offense to lead the club back to contention for the first time since 2009.

Similarly, Seattle is looking internally to fill most of its pitching needs. Felix Hernandez remains the best pitcher ever developed by the organization, as well as its ace, and the Mariners hope rookies Taijuan Walker and James Paxton will quickly ascend to roles near the front of the rotation. Walker, who ranks with Arizona's Archie Bradley as the game's top pitching prospects, has battled shoulder inflammation this spring and likely will open the season on the disabled list.

"Once Walker and Paxton get to the big leagues, people might think they won't hear from the Mariners for a while," farm director Chris Gwynn said. "We've got depth, with guys looking to make names for themselves. We still have a lot of young guys under the radar."

Even with Walker and Paxton departing to Seattle, pitching will remain the strength of the system. Edwin Diaz, Luiz Gohara and Victor Sanchez all profile as mid-rotation starters or better. They're a few years away, however, as only Sanchez has even reached low Class A.

Gwynn also thinks the Mariners are in the process of developing some much-needed power bats. They spent their top two picks in the 2013 Draft and $4,459,100 on sluggers D.J. Peterson and Austin Wilson, and they also like what they've seen from hitters such as outfielders Jabari Blash and Gabriel Guerrero, and third baseman Patrick Kivlehan. Peterson has a higher offensive ceiling than any player in the organization -- Majors or Minors.

"The ball jumps off D.J. Peterson's bat different," Gwynn said. "He's a good hitter with power. He's what I call a full-service hitter. He can hit to right field or turn on balls and hit them out. He can hit them out to center field, too. Right-handed hitters with power like that are worth their weight in gold."

Three questions with Peterson

Many scouts considered Peterson the best all-around hitter available in the 2013 Draft, and the Mariners were thrilled to get him with the 12th overall pick. He batted .303/.365/.553 with 13 homers in 55 pro games before an errant pitch hit him in the face, breaking his jaw and requiring two surgeries.

MLBPipeline.com: How difficult has it been coming back from getting beaned?

Peterson: It's been going good. I would be lying if I said there weren't a little bit of jitters in my first at-bat. But after one pitch, I felt like everything was back to normal. I was good to go. I knew I'd come back, but I just didn't know how quick. I was lucky it took just one pitch.

MLBPipeline.com: The Mariners and the Padres share a Spring Training base in Peoria, Ariz., so do you get to see much of your brother Dustin, San Diego's second-round pick last year? How would you compare the two of you?

Peterson: I see him every day, we go to lunch or dinner. We're from Gilbert, which is 40 minutes away, so my parents are in heaven. My approach is a little more mature than his, because I've seen more breaking pitches and I can adjust to offspeed [pitches] better. As far as raw ability and athleticism, I'd say he has the upper hand.

MLBPipeline.com: Scouts rave about your bat but aren't as high on your defense, questioning your ability to stick at third base. How do you feel about that?

Peterson: It doesn't bother me. It's something I've heard, just like I heard I'd never be a first-round pick if I went to New Mexico out of high school. It's just more motivation to show people they're wrong. I want to show this organization I can stay at third base.

Camp standout: Roenis Elias

When the Mariners extended a non-roster invitation to big league camp to Elias, it was more a reward for a solid 2013 season in Double-A than an opportunity to actually make the club. Yet with the way he has pitched in the Cactus League, he might open the season in Seattle's rotation.

All-Star Hisashi Iwakuma and Walker are expected to begin April on the disabled list, leaving two vacancies for starters. Elias has seized his opportunity, going 3-0 with a 2.04 ERA in five appearances while pitching well in two starts.

The 25-year-old left-hander defected from Cuba in October 2010, and he signed with Seattle the following May for $350,000. Elias arrived in camp with a reputation for throwing four pitches and using at least as many arm angles, but the Mariners have had him focus on maintaining a consistent three-quarters slot. His stuff and command have been more crisp as a result, and he has frozen big leaguers with his curveball.

"He's a Cuban kid there wasn't a lot of talk about, but he's having a very good spring," Gwynn said. "He's been throwing 89-94 with a good curveball and a good changeup. His separator is his athleticism, and he's very, very poised for his age. Stuff just doesn't bother him."

Breakout candidate: Guerrero

The comparisons to his uncle Vladimir are obvious. Like the former American League Most Valuable Player Award winner and nine-time All-Star, Gabriel is 6-foot-3, eschews batting gloves and hasn't met a pitch he won't swing at.

Signed for $400,000 out of the Dominican Republic in 2011, Guerrero spent his first full season in the United States last year at age 19. He struggled early against older competition, but he rallied to bat .306/.340/.396 in the second half. All four of Guerrero's homers came in the final three weeks, a sign that his above-average power potential is starting to turn into production.

Guerrero is still filling out his frame and won't fully tap into his power unless he tightens his strike zone. He fits the right-field profile well, with a cannon arm that ranks as the best in the system and earns a 70 grade on the 20-80 scouting scale.

"Guerrero has a different type style how he does it, but he has really good hands and the ball jumps off his bat," Gwynn said. "His throwing arm is amazing. He still has work to do, but he loves to play the game. And if you love to be out there, you're going to get better."

Jim Callis is a reporter for MLB.com and writes a blog, Callis' Corner. Follow @jimcallisMLB on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.