SEATTLE (AP) — Mariners' left-hander Drew Smyly will undergo Tommy John surgery after being diagnosed with a torn ulnar collateral ligament.

Seattle announced the diagnosis on Wednesday, ending Smyly's hopes of returning this season. Smyly had been on the disabled list since opening day with a flexor strain in his left arm, an injury that occured in spring training after one outing after he pitched for the United States during the World Baseball Classic. Smyly had been rehabbing in the hopes of returning after the All-Star break but Seattle manager Scott Servais said Smyly came out of his last simulated game not feeling great and additional exams revealed the need for surgery.

The operation is scheduled for July 6 and will be performed by Dr. James Andrews. Recovery time is typically 12 to 15 months.