The procedure, which was performed by Dr. William Meyers in Philadelphia, is likely to keep Lillard out at least 6 to 8 weeks, sources told ESPN. The team on Thursday said his status would be re-evaluated in six weeks.
Lillard last played on Dec. 31.
"It wasn't easy at all because I just love being out there. Like, I love being out there playing,'' Lillard said of the decision to have surgery in a story posted to the Blazers' official website. "I've always been available to play but I think the older you get, the more experience that you have, not just in sports but in life, it becomes more important to play chess. My pride might say `Keep fighting it out, get the job done again. Try to get in the playoffs.' And then the older me is saying 'You can't do none of that stuff if you're not at your best.'"
Portland is in 10th place in the Western Conference and the team is 4-7 without Lillard this season. Fellow backcourt star CJ McCollum is out indefinitely after sustaining a collapsed lung.
Lillard aggravated his abdominal injury playing for Team USA at the Tokyo Olympics last summer. He has battled the issue throughout the season as his shooting and scoring numbers have taken a dip. The six-time All-Star is averaging 24 points and 7.3 assists in 29 games.
The Blazers start a six-game road trip Thursday.