Oakland A's closer Trevor Rosenthal underwent thoracic outlet surgery on Thursday and will miss 12 weeks, the club announced.
The A's put Rosenthal on the 60-day injured list. Rosenthal underwent the surgery in Dallas and will remain there until Sunday. He'll be re-evaluated in eight weeks.
Rosenthal was diagnosed with severe neurovascular compression. The procedure involved the removal of his first rib, the club said.
Rosenthal, who signed a one-year, $11 million deal with the A's in free agency, had yet to pitch for the club in the regular season after appearing in four spring training games.
He was put on the 10-day IL with a shoulder injury last week.
The 30-year-old Rosenthal posted 11 saves and a 1.90 ERA in 23 relief appearances in 2020 in stints with the San Diego Padres and Kansas City Royals. He has posted 132 saves and a 3.36 ERA in his career.
--Field Level Media