Manaea was diagnosed with a rotator cuff tendinitis, Jane Lee of MLB.com reports.

EDGE Analysis

This is a tough blow for Manaea and the A's. The southpaw will be shut down from throwing until the discomfort in his shoulder subsides, after which he'll have to build back up to throwing off a mound again. While the A's are hoping Manaea will be able to pitch again this season, there's a possibility that won't happen. Frankie Montas will take his turn in the rotation for the time being.