Arroyo underwent right elbow surgery Wednesday to clean up cartilage and brace a chronic injury to his UCL.
The Mariners expect Arroyo to be ready to play in games again by next April, so he's slated to get a late start to next season. Arroyo was impressive down the stretch for the Mariners after being summoned for his major-league debut in September, going 13-for-35 (.371) with one home run, two steals and a 5:6 BB:K. It's unclear whether Arroyo will be able to play the field right away upon his return, or if the Mariners could limit him to designated hitter initially.