Oakland Athletics closer Trevor Rosenthal will undergo surgery for thoracic outlet syndrome, Jon Heyman of MLB Network reported.
Rosenthal, who signed a one-year, $11 million deal with Oakland in February, is expected to be out for 12 weeks. Heyman reported that Rosenthal had vascular compression so the surgery was needed.
Rosenthal posted a career-best 1.90 ERA last season. He recorded 11 saves, finishing the season with 38 strikeouts in 23 2/3 innings in 23 appearances with the Royals and the Padres.
Injuries are no stranger to Rosenthal, whose 2018 season with the Cardinals was ended by Tommy John surgery. He resurfaced in 2019 with the Nationals and Tigers, but walked 26 of the 85 batters he faced before bouncing back in last year's shortened season. It will be a challenge to do so again, as there are very few pitchers who have successfully recovered from both Tommy John surgery and thoracic outlet syndrome.
With Rosenthal out, the A's will have to decide who will take over the ninth inning. Options include Lou Trivino, Jake Diekman and Sergio Romo.
Oakland squares off against Houston on Thursday night. The Athletics won their first game of the season against the Dodgers on Wednesday after starting 0-6.