The Guardians designated Zunino for assignment Friday, Zack Meisel of The Athletic reports.
Zunino has been ice cold at the plate recently, slashing just .095/.174/.095 since the beginning of June. His release leaves Cam Gallagher and David Fry as the catching options on the big-league roster, but top prospect Bo Naylor is waiting in the wings. Touki Toussaint was called up from Triple-A Columbus in a corresponding move.