UPDATE (2:43 p.m. ET): Timberwolves have announced that forward Jimmy Butler underwent successful meniscus surgery this morning on his right knee. The operation was performed by Team Orthopedic Surgeon Dr. Diane Dahm at Mayo Clinic in Rochester, Minnesota. Butler will be sidelined indefinitely and further updates as to his progress will be issued over the course of the rehabilitation process.

MINNEAPOLIS (AP) -- The Minnesota Timberwolves say Jimmy Butler has had an MRI that revealed a meniscal injury to his right knee.

The Timberwolves did not provide a timeline for Butler's absence Saturday, but it is likely good news that it is a cartilage injury, and not a ligament.

The team stopped short of calling the injury a tear, and coach Tom Thibodeau said he didn't want to speculate on timing. Still, the news Saturday could've been worse for the organization, which feared a season-ending torn ligament after Butler had to be helped off the floor Friday night in a loss at Houston.

"The big thing is ruling out the ACL, that would've been an extended amount of time, so we're hopeful that it's not too long," Thibodeau said.

Nemanja Bjelicao started in Butler's place on Saturday night against the Chicago Bulls.

"A guy like Jimmy, you don't replace him individually, you have to do it collectively," Thibodeau said.

Butler was hurt Friday night at Houston in the third quarter and had to be carried off the court by a pair of teammates. The Wolves lost 120-102 to the Rockets and the All-Star had the MRI on Saturday at Mayo Clinic.

The Wolves said more updates on Butler's progress would be issued when information became available.

In his first season with Minnesota, Butler has helped lead the team to the thick of the Western Conference race, averaging 22.2 points. They were in fourth place before play Saturday, in position to end a 13-year absence from the playoffs.