Williams, 31, was injured during the third quarter of the Bears 27-21 win over the New York Giants Thursday night.
It's just another blow to the already thin Bears defense, who have lost defensive tackles Henry Melton and Nate Collins to season-ending injuries.
Rookie Jonathan Bostic is Williams' most likely replacement at the position. Bostic played 21 snaps for the Bears last night and was critical of his performance.
“I made a lot of mistakes out there," Bostic said to the Chicago Tribune. "I’ve got to get settled back in and just play by our rules.”
Williams made four starts this season for the Bears (4-2), recording 27 total tackles and two sacks.