Perales was removed from Saturday's start at Double-A Portland with an injury to his throwing arm, Geoff Pontes of Baseball America reports.
Perales stepped off the mound after throwing a pitch and was hanging his throwing arm. He was visited by a trainer for a brief moment before exiting to the dugout. Saturday's outing was just Perales' second at Double-A and he tossed five scoreless innings with seven punchouts in his Portland debut. An update on his status should come later this week.