Boxberger, 28, underwent surgery on March 17 to repair the adductor brevis muscle, which was performed by Dr. William Meyers in Philadelphia. He missed the first 48 games. Boxberger had a 3.38 ERA with eight strikeouts in 5 1/3 innings in six rehab appearances with three minor league clubs.
Alex Colome has 12 saves in 12 opportunities in Boxberger's absence. Manager Kevin Cash indicated Boxberger would be eased back into the closer's role.
The Rays placed right-hander Ryan Webb on the 15-day disabled list, retroactive to Friday, with a right pectoral strain. Webb had a 3.31 ERA in 17 relief appearances. Webb becomes the third player the Rays have placed on the disabled list since May 14.