The Giants placed Susac on the 10-day injured list Friday with a lower-back strain, Alex Pavlovic of NBC Sports Bay Area reports.
Susac was forced out of Thursday's game in the sixth inning with back tightness, and his injury will keep him out until at least July 6. Eric Haase will presumably take over as San Francisco's main backstop until Susac returns. However, Drew Cavanaugh will get the nod behind the plate Friday after coming up from Triple-A Sacramento in a corresponding move.