NathanEovaldi, who was placed on the IL Saturday with a loose body in his right elbow, will undergo surgery Tuesday and be lost to the team for four to six weeks.
Eovaldi, who allowed one run in six innings last Wednesday in New York, had difficulty straightening out his right arm the next day.
He underwent a similar procedure last year while with the Tampa Bay Rays and missed exactly two months. But that surgery came as Eovaldi was still recovering from Tommy John surgery, which further slowed down his recovery.
Eovaldi has undergone Tommy John surgery twice in his career. Tuesday's procedure will mean a total of four surgeries on his right elbow.
In the meantime, the Red Sox will, for the foreseeable future, use Hector Velazquez in his spot in the rotation.
Ken Rosenthal of The Athletic was first to report Eovaldi's scheduled surgery.