Jonah Heim and Mark Leiter Jr. each brought niche skills to the A's in 2026.

The A’s injury report indicated Shea Langeliers will have surgery for a torn meniscus in his right knee and Mark Leiter Jr. will have surgery to repair a right hip impingement.

The A's will lose two key contributors to the operating table Tuesday morning, but received encouraging updates on Jeffrey Springs and Ryan Lasko's recovery.

The moves open two 40-man spots as the A's welcome back their hottest reliever before he landed on the IL

Mark Leiter Jr. is headed to the IL with a hip impingement, Zack Gelof's hit streak is on pause, and top prospect Wei-En Lin's MRI results remain unclear

Baseball has a way of writing its own scripts, and for Mark Leiter Jr., his latest chapter couldn’t have been more ironic. The former New York Yankees reliever recently made headlines by claiming the organization “ruined” him by not trusting…

Free agent right-hander Mark Leiter Jr. has reached agreement on a $2.85 million, one-year contract with the Athletics, according to a person familiar with the deal. The person spoke to The Associated Press on condition of anonymity Thursday because the move won't be finalized until Leiter passes a physical. Leiter's father and uncle also pitched for the Yankees.