Manaea left Monday night's start after only 4.1 innings due to a left pronator muscle strain in his forearm, reports Jane Lee of MLB.com.

EDGE Analysis

This is a really bad break for Manaea and for the A's considering Manaea is their top pitching prospect. There is no timetable yet for the injury, but a forearm injury to a young pitcher is almost certainly to be dealt with cautiously, even if not serious.