Barkley, who did not travel with Everton's squad to a pre-season training game in the Netherlands and also missed a trip to Tanzania earlier this month because of the injury, is now a doubt for the start of the new season.
Everton begin their Premier League campaign at home to Stoke City on Aug. 12.
"Ross Barkley underwent surgery today on his groin," Everton said in a statement on their website. "The surgery has been a success and he is expected to be able to return to play in approximately four weeks."
Barkley, 23, has yet to sign a new contract with Everton and has been linked by British media with a move to Tottenham Hotspur.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
(Reporting by Toby Davis; Editing by Toby Chopra)
