The son of two-time All-Star and World Series champion Al Leiter, Jack turned down first-round money as a New Jersey high schooler in 2019 to attend Vanderbilt, where he emerged as the No. 2 overall pick two years later. In his lone full college season, he no-hit South Carolina in his first Southeastern Conference start, tied teammate Kumar Rocker for the NCAA Division I strikeout crown (179 in 110 innings) and pitched the Commodores to the College World Series finals. After signing for $7,922,000, he spent most of the last two years in Double-A struggling with his delivery as his stuff and control regressed.
Leiter's fastball continues to sit at 93-96 mph and top out at 98 with plenty of induced vertical break and riding life, but it's not quite the elite pitch it was in college because he hasn't commanded it well and pro hitters have crushed it when he doesn't locate it up in the zone. He has added velocity and depth to a mid-80s slider that was his most effective pitch in 2023. He's now having trouble getting strikes or chases with an upper-70s curveball that used to be his best secondary offering and doesn't show much faith in a mid-80s changeup with modest fade.
Leiter spent two stints on the developmental list twice last year, for a week in June and six weeks later in the season, so he could focus on improving his mechanics. He's an explosive athlete who creates plenty of extension, but his timing can get out of whack, leading him to open early and lose direction toward the plate, which hampers his stuff and his ability to locate it. The Rangers are optimistic that his off-field work ironed out those kinks, and he'll need to in order to recapture his previous ceiling of a frontline starter.