Mark Leiter Jr. has ridden his reverse splits to a steady job in the Cubs’ bullpen, and he’s liable to keep it for a while, since he’s effective and cheap. He’s been good for 0.6 WAR in 22⅔ innings, with 33 strikeouts and seven bases on balls, and is currently riding a .926 WHIP.
He throws a fastball and a splitter. His splitter is a weapon. He gets most of his strikeouts with it. It’s a difference-maker. He also has a sinker, cutter, and a curve, but doesn’t use them often, especially against lefthanders.
When he moved to the bullpen, Leiter’s splitter became a weapon, one of the best in baseball. Opponents hit just .079 off the pitch and had an expected batting average of .095 on it, per Baseball Savant. No pitch in baseball — with a minimum of 100 plate appearances ending on a pitch — was more effective. He struck out 53 hitters with the pitch and had a staggering 53.6% whiff rate on it.
“It’s a pitch that has become him,” catcher Yan Gomes said. “He’s got a good enough arsenal that he can do well with his other pitches. But he knows his bread and butter is his split.” — Andy Martinez.
The 32-year-old Leiter is on a one-year deal for $850,000. I wouldn’t be at all surprised if the Cubs offered him another year at some point. That arm isn’t overworked by any means, though Leiter did have Tommy John surgery in 2019, and became a reliever after that, with his next appearances in the major leagues coming with the Cubs.
Leiter was DFA’d originally for Eric Hosmer, and the Cubs signed him to a minor-league deal February 2, 2023. He was on the major-league roster at the end of Spring Training and had to be added back to the 40-man roster.
He’s always been on the edge of release. Leiter was originally brought up to replace the injured Alec Mills and earned his way onto the squad. He even took the ball for a few starts.
I don’t think he’s due for DFA any time soon, as he has become a bullpen mainstay by virtue of getting outs when he is asked. Here’s a pretty good inning he threw against the Dodgers earlier this year: