Coach John Beilein announced Bielfeldt's operation at an offseason news conference Tuesday. The 6-foot-7 Bielfeldt played 89 minutes in 19 games in 2013-14, and Michigan won the Big Ten title.
The Wolverines were already facing a challenge next season after losing Nik Stauskas, Glenn Robinson III and Mitch McGary early to the NBA. Michigan also loses big men Jordan Morgan and Jon Horford. Morgan used up his eligibility, and Horford left the team to transfer.
If Bielfeldt's injury lingers, Michigan may need even more of a contribution from 6-foot-9 Mark Donnal, who redshirted last season.