The injury occurred during the Bucks' Nov. 6 game against the Portland Trail Blazers. He was able to play for the next three games, the Bucks said, but told staff that he was experiencing "discomfort" during Wednesday night's 116-113 loss to the Memphis Grizzlies.
The Bucks said that Henson was evaluated Sunday by orthopedic surgeon Dr. Carole Vetter. The team said that the surgery will be scheduled soon and that a timetable for return will be provided after the operation.
"It's tough," Brook Lopez told ESPN. "John brings a lot of energy. He has been shooting the ball super well. He picks up our defense when he comes in the game. We want him to take care of himself, and we're going to rely on whoever is next to step up and be ready."
Through 14 games this season, Henson -- who comes off the bench -- averaged 5.6 points, 5.1 rebounds and one assist per game.
The Bucks, who play the Chicago Bulls on Friday night, will also be without rookie guard Donte DiVincenzo for at least the next three games. He suffered a minor left quadriceps strain against the Grizzlies, the team said.