Clevinger is expected to be sidelined for around six weeks after being diagnosed with an MCL sprain in his right knee, Jason Mackey of MLB.com reports.
Clevinger will be immobilized for several weeks before resuming workouts. The veteran right-hander has been pitching out of the bullpen at Triple-A Indianapolis, allowing five runs with a 9:5 K:BB across 8.2 innings. He won't be an option for the Pirates until sometime in June, at the earliest.