Dr. David Fischer, the team's orthopedic surgeon, successfully performed the procedure at TRIA Orthopaedic Center. The recovery time for the injury is typically six weeks.
Friday was the second time this year Lee has undergone surgery on his left knee. He had a cartilage tear fixed and some loose cartilage removed in March at the end of UCLA's season.
Lee then entered the NBA Draft, ending his three-year career with the Bruins. The Bulls picked him in the second round and dealt him to the Timberwolves, who signed Lee to a contract earlier this month.