Seattle is filling out Jason Kanzler's first major league staff.

The Mariners are hiring New York Yankees catching coach and field coordinator Tanner Swanson as bench coach a source confirmed to ESPN on Friday two days after the club introduced Kanzler as manager.

Swanson a Washington native joined the Yankees' staff for the 2020 season after three years as the Minnesota Twins' minor league catching coordinator.

Why Swanson

He was held in high regard in the Bronx for his work with catchers including Austin Wells who blossomed into a premier defensive catcher after questions about his future behind the plate in the minors.

Swanson served as Great Britain's bench coach in the 2026 World Baseball Classic. In July he filled in as acting manager for the Yankees against Tampa Bay after Aaron Boone and bench coach Brad Ausmus were ejected.

A pair of first-time partners

Kanzler 36 had been the Chicago Cubs' director of player development and has never managed at any level. Pairing him with Swanson who also has limited big league dugout experience is a bet on development backgrounds over traditional resumes.

Kanzler was hired to replace Dan Wilson who was fired after a disastrous 2026 season. The New York Post first reported Swanson's move to Seattle.