The veteran right-hander can now sign with any club interested in acquiring his services.
On Monday, the Rays activated the right-hander off the disabled list and promptly designated him for assignment.
Glover, 31, went on the 15-day disabled list on July 11 with a left calf strain and the Rays used his roster spot to activate Troy Percival. But upon Glover's return, the Rays did not feel they had anyone in the bullpen they wanted to bump in favor of Glover, who was 1-2 with a 5.82 ERA in 29 games this season.
Glover, who is making $1.075 million this season, appeared in 67 games for the Rays in 2007 and posted a 6-5 record with a 4.89 ERA.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.