After leaving Saturday's 8-3 victory against the Nationals with discomfort in his right elbow after releasing a pitch, Rays reliever Jason Isringhausen will be placed on the 15-day disabled list.
Rays manager Joe Maddon said after the game that Isringhausen was being looked at by team doctors in the training room.
"He was really starting to throw the ball well, and there's concern," Maddon said. "I don't know what level, but there's concern."
Isringhausen was not available for comment.
The 36-year-old right-hander had surgery to repair a torn flexor tendon in his elbow in September. He was signed in the offseason to a Minor League contract after spending the past seven seasons with St. Louis, where he became the Cardinals' all-time saves leader.
Isringhausen is seven saves shy of 300 for his career. In eight appearances since coming off the disabled list this season, he was 0-1 with a 2.45 ERA.