Jennings had been out since April 26 with left knee bursitis. The operation was meant to clean up inflamed tissue.
Rays manager Kevin Cash said there was no timetable for Jennings' return, but called the 3-4 week timeline a "best case scenario."
"I'm happy for Desmond, I think we all are," said Rays manager Kevin Cash, according to RaysBaseball.com "He's been battling and frustrated by an injury that there was some uncertainty on. Hopefully we found some clarity. The doctors went in there, scoped it out, cleaned some stuff out and hopefully it won't be too long of a rehab."
Marc Topkin of the Tampa Bay Times reports Jennings is likely to miss eight weeks. That timetable means a mid-August return for the 28-year-old outfielder, who has hit .222 in 18 games this season.
- Jeremy Woo