The Timberwolves announced Thursday that Butler had the elective procedure on Tuesday. The team said Butler has already returned to offseason activities.
Butler, who missed 21 games last season with an injury to his right knee, averaged 22.2 points per game for the Timberwolves after arriving in a trade with Chicago. He helped lead the Wolves to their first postseason appearance since 2004. Butler can opt out of his contract and become a free agent after the upcoming season.