Robinson underwent the procedure to repair medial and lateral ligaments in his left ankle.
The 23-year-old was injured driving to the basket during a scrimmage in practice on Sept. 29.
The 6-foot-6, 222-pound Robinson, the son of former NBA star Glenn Robinson, averaged a career-high 6.1 points and 3.6 rebounds in 69 games (27 starts) last season. The 2017 NBA slam dunk contest champion shot 39.2 percent on 3-pointers.
Robinson was a second-round draft pick of the Minnesota Timberwolves in 2014 after leaving Michigan following his sophomore season. In 149 regular-season games for the Timberwolves, Philadelphia 76ers and Pacers, Robinson has averaged 4.4 points on 44.8 percent shooting.