Matt Kawahara of the San Francisco Chronicle reports that Jefferies underwent Tommy John surgery Friday to repair UCL damage in his right elbow.
The Tommy John procedure is the second of Jefferies' career; he previously had the reconstructive elbow surgery in 2017. The elbow surgery comes just three months after he underwent thoracic outlet syndrome surgery, and the cumulative effects of the two procedures in quick succession cast significant doubt about his future. At a minimum, Jefferies will be sidelined for the 2023 season, and he may not be a safe bet to receive full clearance for spring training in 2024. The 27-year-old could be a non-tender candidate this winter.