Former Mariners reliever Carson Smith will undergo Tommy John surgery on his right throwing elbow and miss the next 9-12 months, the Red Sox announced Tuesday.
Smith, 26, made three appearances for Boston after straining the flexor muscle in his right arm March 21. He came off the disabled list May 3, but subsequent attempts to regularly work him into the bullpen's rotation failed and he returned to the DL this past Friday.
He was diagnosed with a torn ulnar collateral ligament. Dr. David Altchek is expected to perform the reconstructive surgery Tuesday in New York
Smith was a dominant reliever for Seattle in 2015, going 2-5 with a 2.