Briggs alternated the first two series with backup Brian Iwuh, before leaving the game with the Bears leading 7-0. It's unclear as to whether Briggs reinjured the ankle or just couldn't continue playing on the injury he originally sustained two weeks ago against the Carolina Panthers.
Briggs sat out the Bears' 23-20 loss to Seattle, but the linebacker was able to practice twice during the week.
Cornerback Zack Bowman headlined the Bears' inactives for the game. He was officially ruled out due to a sprained right foot.
Two rookies were active for the first time this year: cornerback Joshua Moore and defensive end Barry Turner.
Moore, a 2010 fifth-round draft choice, added depth to the cornerback position with Bowman out, and Turner -- elevated from the practice squad Tuesday -- replaced fellow rookie Corey Wootton in the defensive end rotation.
Bears head coach Lovie Smith spoke highly of Turner's pass-rush potential on Friday.
"When you talk about defensive end, first off, you say can a guy rush the passer," Smith said. "That's what we've seen from him. [He's a] live body, athletic, with speed off the corner. We don't have a lot of guys like him, as far as what he brings to the table.
Jeff Dickerson covers the Bears for ESPNChicago.com and ESPN 1000.