The Mariners designated Gosewisch for assignment Sunday.
After acquiring reliever Ryan Garton from the Rays in a trade Sunday, the Mariners didn't have room on the roster for Gosewisch, a 33-year-old catcher who didn't project as a regular option at the position. Gosewisch, a career .190 hitter over parts of four seasons in the big leagues with the Diamondbacks and Mariners, will look to latch on with another organization to serve as catching depth in the upper minors.