Athletics Sign Mark Leiter Jr.

December 17th: The A’s have officially announced their signing of Leiter.

December 11th: The Athletics have reportedly reached an agreement with right-hander Mark Leiter Jr. on a one-year, $2.85MM contract. The signing is still pending a physical. Leiter is a client of VC Sports Group.

Leiter, 35 in March, made his big league debut back in 2017 but didn’t fully establish himself at the big league level until joining the Cubs in 2022. He served as a swing man and long reliever for Chicago that year, with a 3.99 in 67 2/3 innings of work in that role, but moved to a short relief role full-time in 2023. In 100 2/3 innings of work for the Cubs over the next two seasons, Leiter pitched to a 3.75 ERA with a 3.12 FIP while striking out 30.9% of his opponents and walking 8.8%.

Those exciting peripherals were enough to convince the Yankees to swing a trade for the right-hander at the 2024 trade deadline, but he struggled in New York even as his peripheral numbers remained strong. In 70 innings of work for the Yankees over parts of two seasons with the club, Leiter posted a 4.89 ERA despite a 4.07 FIP. In 2025, Leiter struck out 24.7% against a 7.8% walk rate while generating grounders on 45.5% of his batted balls allowed. Unfortunately for the righty, the results weren’t there enough for the Yankees to tender him a contract last month, and he wound up reaching free agency a year earlier than anticipated.

Headed into 2026, the A’s can expect Leiter to be a solid middle relief arm at least. His 4.15 ERA over the past four seasons is exactly league average (100) by ERA+, and the right-hander’s impressive splitter actually makes him particularly effective against left-handed batters. In 104 2/3 innings of work against lefties the last three years, Leiter has posted a 2.49 ERA and 2.57 FIP with a 32.1% strikeout rate. With league average results overall and elite numbers against lefties, Leiter has a much higher floor than a typical non-tendered middle relief arm, which is surely why he was able to command a solid guarantee even coming off a tough year in New York.

Leiter hasn’t managed to play up to his peripherals throughout his career, but if he can do so he could wind up a valuable setup man for the A’s this year. The righty’s 3.13 SIERA over the past three seasons ranks 13th among relievers with at least 150 innings of work since the start of the 2023 season, and that puts him on a similar level to well-regarded late-inning arms like Luke Weaver. Leiter’s .359 BABIP and 66.5% strand rate over the past two years indicate extremely poor fortune when it comes to batted balls and sequencing; if those numbers experience enough positive regression to get within spitting distance of league average, Leiter’s a good bet to be impactful at the back of the A’s bullpen next year.

It’s been a quiet offseason for the A’s so far, though there’s certain reasons for optimism regarding the club’s future. Nick Kurtz emerged as a potential superstar this year, and he’s backed by a core of exciting positional talent like Brent Rooker, Shea Langeliers, Jacob Wilson, and Lawrence Butler. The club’s pitching staff needs plenty of work if the team is going to contend in 2026, but adding Leiter to a bullpen that already houses respectable arms like Hogan Harris and Michael Kelly should be a small step towards accomplishing that goal. Jeffrey Springs and Luis Severino remain in the fold as solid back-of-the-rotation veterans, though it remains to be seen how much A’s ownership is willing to spend in order to augment that group. Whether the A’s are facing significant budget constraints or not, however, bringing Leiter into the fold as a reliever with possible late-inning upside on a relative bargain can only be a good thing for the club.

Robbie Hyde of Foul Territory first reported the agreement. Janie McCauley of The Associated Press reported the $2.85MM guarantee, after ESPN’s Jesse Rogers first noted it would close to $3MM.