Slow and steady for the big righty
After an accidental break caused by Kate contracting the black plague, we’re back with another installment of our prospect countdown today. If you missed Max’s writeup of #18 Brock Rodden, featuring quotes from the man himself, make sure to check that out, or catch up with everything in the series here. Today we’re continuing to move down the list, first up with #17, RHP Jeter Martinez.
You might recall that Kate profiled Martinez last spring training, fresh off a strong start in the Dominican Summer League that saw him named to an All-Star team and anticipating making his stateside debut. His first taste of the Arizona Complex League wasn’t quite as strong, but there’s still big upside to the 6’4”, strong-bodied righty, who turns 19 in just about a week.
As an amateur, Martinez built himself into a prospect working with Showtime Athletes in Florida, moving there to train from his native Mexico as a young teenager and gradually building up from throwing in the high 70s to the mid-90s. He caught the eye of the Mariners’ international scouting department, joining the 2023 signing class with the second-highest bonus as one of the most well-regarded signings out of Mexico.
Martinez’s fastball has some natural sink, and he pairs it with a cutter that has more ride, coming in a few ticks off the fastball, that he can generate ground balls with. As his primary swing-and-miss weapon, the fastball is still Martinez’s bread and butter, but it’s grown harder for him to command the pitch as he’s added velocity. After his strong DSL debut, Martinez said his focus was trying to cut down walks in his first season stateside. That didn’t pan out, as he struggled even more to command the zone against the slightly-more seasoned hitters in the ACL, still posting excellent strikeout numbers but with a backslide in his command.
Part of improving his command will also be in building up his stamina over a long season; Martinez walked only one hitter per appearance in five of his first six three-inning starts in the ACL, but then walked three batters or more in all but one of his final seven appearances. He did end the season on a high note, striking out a season-high eight batters over four innings in his final appearance. While Martinez’s large frame is a boon for a potential starting pitcher, it also means more square footage to condition, train, and get coordinated, and sometimes watching him lose his mechanics just feels like a failure to corral all six-foot-four-plus of him.
Young pitchers are often doubly challenged with refining their command while also working on developing their arsenal, and Martinez is no different. After working on adding a sweeper prior to last season, Martinez has challenged himself further, as he’s trying to deepen his arsenal by adding a curveball that shows some promising 12-6 movement but inconsistent shape, per developmental videos he’s posted on his social media channels. A curveball is a natural fit for Martinez’s arm action, which is somewhat long, and smoother rather than explosive. He also throws a changeup that he has more confidence in, but like the curveball, it’s more of a developmental offering at present.
Martinez remains a project, and his stateside debut wasn’t as thrilling as his DSL campaign, but he ranks inside our top twenty for now given his ability to miss bats, his prototypical starter’s size, and the promise of that rich arsenal. This year will be an important one to see how well he can harness his command in order to keep developing that arsenal; something to keep an eye on will be when the organization feels he is able to make the leap to full-season ball in Modesto.