The Bears had placed Freeman on injured reserve Tuesday.
The team signed Freeman to a three-year deal last offseason after he spent the previous four seasons with the Indianapolis Colts. He missed a combined seven games due to injury in 2014-15.
When healthy, Freeman is one of the NFL's best linebackers. Pro Football Focus graded him as the NFL's best linebacker in 2016 with a 93.8 overall grade, and he had just one missed tackle with 40 made tackles while in coverage.
Losing Freeman creates a massive hole in the Bears defense. Christian Jones is likely to move into the starting lineup opposite Danny Trevathan to take his place.