Freeman posted a message on his Instagram page noting he suffered the injury on the first play of Chicago's 23-17 loss to the Atlanta Falcons:
Jeff Dickerson of ESPN.com noted that means Freeman played 55 snaps with the setback. The Instagram message also revealed Freeman suffered a concussion during the game.
Losing Freeman is a significant blow for the Bears. Dickerson pointed out he led the team with 110 tackles in 2016 even though he was suspended four games for violating the NFL's performance-enhancing substances policy.
It was the fourth time in Freeman's career he tallied more than 100 tackles, the other three of which came when he was a member of the Indianapolis Colts.
According to Dickerson, Nick Kwiatkoski will take Freeman's spot in the starting lineup for Sunday's contest against the Tampa Bay Buccaneers.