The Seattle Mariners signed catcher Andrew Knizner to a one-year MLB contract, the team announced in a press release on Tuesday. The Knizner signing brings the Mariners' 40-man roster to 39 total players at the moment. Knizner, a veteran backstop, will give Seattle extra depth at the position.
The 30-year-old spent the first five seasons of his big league career with the St. Louis Cardinals, where he played from 2019-2023. He spent 2024 with the Texas Rangers and 2025 with the San Francisco Giants. He doesn't offer much offensively, holding a career .221/.281/.316 slash line to go along with 19 total home runs.
Knizner knows how to handle a pitching staff, though. He will serve as a reliable backup for Cal Raleigh in Seattle during the 2026 season.
Why the Mariners needed another catcher
Catching prospect Harry Ford was traded to the Washington Nationals earlier in the offseason. Mitch Garver served as Seattle's backup catcher in 2025, but he is still a free agent as of this story's writing. The Mariners' signing of Knizner suggests Garver likely won't be back in 2026.
Ford may have been a candidate to replace Garver. However, Seattle ultimately moved the prospect in the aforementioned trade. With minimal options aside from Raleigh, the Mariners needed a backup catcher — which led to the Knizner signing.
Seattle features a potential playoff roster. However, the Mariners are still looking for ways to improve. Adding more offense around stars such as Raleigh, Julio Rodriguez and Josh Naylor will be important. Their pitching has depth, but Seattle would benefit from adding another hurler or two in the bullpen.
