Loney, who both throws and hits left-handed, sustained the injury during Sunday's game against the Oakland Athletics.
The 31-year-old previously spent time on the disabled list in April with a strained right oblique muscle.
In 30 games this season, Loney is hitting .275 with two home runs and 11 RBI.
After Sunday's game, Tampa Bay optioned pitcher Preston Guilmet to Triple A Durham. The Rays recalled infielders Tim Beckham and Jake Elmore from Durham on Monday to take Loney and Guilmet's places on the roster.
The Rays (24–21) are in first place in the AL East. They host the Seattle Mariners on Monday.
- Molly Geary