One of the greatest strengths of the Astros’ organizational talent pool is their upper level pitching, as their strong major league rotation is backed by a strong of big-league ready arms at the Double and Triple-A levels. After wunderkind Forrest Whitley, the hurler in that group with the highest ceiling is likely Cuban southpaw Cionel Perez (or former Aggie Corbin Martin), who made his major league debut in 2018.
Perez was signed prior to the 2017 season to a $2 million contract after an initial $5+ million contract was voided due to medical concerns. Perez didn’t have the most impressive debut, failing to miss bats while splitting time between starting and relief across three levels. It wouldn’t take long for him to show the potential that made him a seven-figure signee though, as Perez returned in 2018 looking like a new pitcher. He struck out 30% of opposing hitters and posted a 2.60 FIP in Corpus before being promoted to the Fresno bullpen where he continued to miss bats but began to see his command wobble in a short stint.
With a pressing need on the major league roster for a lefty reliever, Perez was called up to make his major league debut in the second half, and ended up appearing in 11 games for Houston. While he allowed just six hits in his big league appearances, three of them left the yard, and he issued seven free passes. Prior to his promotion to Fresno, the first stop at which he was used purely as a reliever, Perez’s command numbers had been solid, and it would appear that after moving to short relief he began to overthrow a bit and lose his location.
There’s no question that Perez has the stuff to succeed in either role. His fastball is absolutely electric, averaging 95.6 MPH out of the pen with the big club, which puts him near the top of the charts for left-handers. As a starter he loses a couple of ticks, but the pitch shows plus regardless. Perez throws two breaking balls, leaning on a hard slider in the majors, and his changeup and curveball are also legitimate offerings. As a lean, sub-six foot hurler with premium velocity and two pitches that stand out above the rest of his arsenal, it makes a lot of sense to project a long term bullpen role for the 22 year old. His fastball gains at least a half-grade in short work, and his so-so changeup becomes less of a concern.
That said, he lacks a swing-and-miss offspeed offering which is rare among late-inning stoppers and there is a template for success in the rotation for a pitcher like Perez. Though he lacks high-octane offspeed stuff, Perez is praised for his feel for pitching and there was enough confidence in his changeup for him to use it fairly liberally in relief work last season. The Astros do have a need for left-handed help in the bullpen, but thus far Perez’s pitchability has looked stronger in a starting role, and the Astros’ bullpen makeup doesn’t warrant altering a talented pitcher’s development path at this point. Perez made good on his upside as a starter in the minors last season, and unlike the Framber Valdez/Rogelio Armenteros tier of Astros pitching prospects, there is a real possibility that Cionel can turn into a mid-rotation starter at the big league level.
Given the Astros’ depth, even after trading Trent Thornton and losing Charlie Morton, I think that they would be best-suited assigning Perez to the rotation in Triple-A Round Rock to begin 2019. With a bit more seasoning, Perez could be ready to make spot starts or fill in for an injured starter in Houston by the summer. Should he falter in the rotation, there is a third option the Astros could pursue. FanGraphs prospect writer Kiley McDaniel included Perez in an August piece in which he explored candidates for the opener role used to great effect by the Rays in 2018. McDaniel drew parallels between Perez and ace opener Ryne Stanek, as both have plus fastballs and solid command, but lack a standout offspeed offering. Personally, I’d like to see the Astros explore multi-inning relief roles more extensively after the success that Chris Devenski had in a version of one, and Perez is a prototypical super-reliever. There is enough talent here that the Astros should be able to find a role in which Perez can thrive- 2019 should elucidate which it might be.