Mbakwe sustained the injury while going up for a rebound Sunday in the second half of Minnesota's 86-70 loss to Dayton in the championship game of the Old Spice Classic at Orlando, Fla.
The senior tore the anterior cruciate ligament in his right knee on the play.
"Trevor's done everything we've asked him to do in his time here at the University of Minnesota. He's been through an awful lot," Gophers head Coach Tubby Smith said Monday. "That says a lot about his toughness to be able to recover from the things he has already endured."
Mbakwe was leading the Gophers (6-1) in points (14) and rebounds (9.1) per game through seven contests.
His 327 rebounds last season were the third-most in a single season at Minnesota and the most since Jim Brewer collected 331 in 1970-71.