The Timberwolves announced that Butler's surgery, performed at the Mayo Clinic in Rochester, Minnesota, was successful. He has been ruled out indefinitely.
On Saturday, Butler was telling close confidants that he was optimistic about his chances to come back before the playoffs begin, should the Timberwolves clinch their first postseason berth in 13 seasons.
Butler suffered the noncontact injury in the third quarter of the Timberwolves' road loss to the Houston Rockets on Friday.
He is averaging 22.2 points, 5.4 rebounds and 5.0 assists in 56 games for a Timberwolves team that sits in third place in the Western Conference.
"It still sucks he has a tough injury; all injuries are tough, but the doctors are saying some good things, so we'll see in a few weeks maybe."
After Monday's game against the Sacramento Kings, the Wolves will have eight straight games against teams with an above-.500 record.
Information from ESPN's Nick Friedell was used in this report.