Prospect Keller: 'One day I want to be the ace'

BRADENTON, Fla. -- Mitch Keller scaled the mound on Field 4 at Pirate City late Tuesday morning, staring down four of his own teammates during a round of live batting practice. There was a protective screen set up just behind him to provide cover for coaches, staff and several of the Pirates’ most experienced starting pitchers -- Chris Archer, Joe Musgrove and Steven Brault among them -- who had gathered to watch.

Keller intends to join that group for good this season. Pittsburgh’s top prospect is competing for a spot in the starting rotation during Spring Training, sure, but he came to camp aiming for more than just a permanent arrival and survival in the Majors.

“Ultimately, one day I want to be the ace, so that’s what I’m trying to be right now,” Keller said. “Try it now, and if I don’t fall along those lines, then keep working for it. If I’m trying to be the ace of the team right now, then I think that’s going to bring out the best in me.”

The Pirates would certainly like to see the best version of Keller in their rotation. The 23-year-old right-hander can’t concern himself with the organization’s bigger-picture issues, but his success is important in several regards:

1. In recent years, the Pirates saw top pitching prospects like Gerrit Cole and Tyler Glasnow scratch the surface of their potential in Pittsburgh, only to immediately blast through that ceiling elsewhere. That simply can’t happen with Keller, who posted a 7.13 ERA in 11 starts as a rookie last year.

2. General manager Ben Cherington’s plan for a “team build,” not a rebuild, is dependent upon the talent already on the roster or in the upper levels of the Minor League system. It’s not hard to see that Keller, perhaps the club’s best short-term hope for high-upside rotation help, could be a prominent part of Pittsburgh’s next core.

3. The Pirates overhauled their pitching program over the offseason, bringing in a forward-thinking and data-driven pitching coach, Oscar Marin, while fortifying their analytics staff and increasing their implementation of technology. Keller isn’t the only pitcher who stands to benefit from those changes, of course, but he will serve as an example of the program’s effectiveness one way or another.

The good news? Keller has already bought into the analytical approach led by Marin and bullpen coach Justin Meccage. After his first live batting practice session, Keller said he was focused on sharpening his breaking balls because he plans to throw more of them -- and fewer fastballs -- than he did a year ago.

There is no denying the quality of Keller’s arsenal. In the Majors, his fastball averaged 95.4 mph with high-end spin that ranked in the 91st percentile among Major League pitchers. Opponents struggled mightily against his breaking balls, batting .200 with a .289 slugging percentage against his slider and .133/.133 against his curveball.

Yet Keller allowed 72 hits in 48 innings during his debut season, and opponents batted .461 with a .719 slugging percentage against his fastball. How did that happen? Keller thought he leaned too heavily on his four-seamer, which he threw 59.5 percent of the time last year.

“I knew I threw a lot of fastballs, but I didn’t really know the numbers to a ‘T’ or anything like that,” Keller said. “But sitting down with Oscar and [Meccage], they went over it this offseason and really dove deep into my usage, my splits to righties and lefties. It was pretty high on the fastball, which is probably one of the reasons my fastballs got hit around more than usual -- because I was throwing it more than usual, and guys were just sitting on it.”

Keller, a visual learner by nature, said it all clicked into place when Marin and Meccage showed him those numbers. They’ve also helped Keller make better use of the Rapsodo data captured during each of his bullpen sessions. Those technological tools provide instant feedback on the mound, so Keller can further back up his feelings with facts.

“There is some really good stuff coming from my stuff last year, so we just really looked at that stuff -- not the most negative things,” Keller said. “We looked at where my fastball got hit and where we’re trying to avoid there, but we really looked at where my stuff plays the best and went with that.”

For all the lessons he learned by struggling in the Majors, Keller may have gained something just as important down the stretch: a sense of belonging. Keller said he feels more at ease than he did last spring, and he’s carrying himself with more confidence. Archer, Musgrove and Brault encouraged their younger teammate every time he executed a pitch during Tuesday’s live BP session.

“When you have experiences, you’re able to gauge yourself -- especially against Major League hitters -- and he does have elite stuff,” manager Derek Shelton said on Tuesday. “If you watch a couple of the breaking balls he threw today, you’re not going to see those pitches very many places.”

Ideally, the Pirates will see those pitches at PNC Park in about six weeks -- and for many years after that.