O'Malley was removed Monday in the first inning of Triple-A Tacoma's game after sustaining a concussion, Tacoma radio play-by-play announcer Mike Curto reports.
O'Malley apparently suffered the head injury after tripping over the pitcher's mound while pursuing a popup. The utility man has had a rocky season on the health front, as he was sidelined for the beginning of the campaign with appendicitis and also missed significant time while recovering from shoulder surgery. The concussion could keep him out of the mix for a promotion to the Mariners when rosters expand in September.