Athletics starting pitcher Sonny Gray underwent successful surgery to repair a torn ulnar collateral ligament in his left thumb Friday, according to the San Francisco Chronicle.

Gray suffered the injury during the American League Division Series against the Tigers. His thumb is expected to be fully healed in time for spring training next year.

Gray finished the season 5-3 with a 2.67 ERA and a 1.11 WHIP over 12 appearances (10 starts).