Right tackle Rick Wagner (ankle) and center Travis Swanson (concussion) were both ruled out by the Lions on Thursday.
Wagner sustained his injury versus the Baltimore Ravens on Dec. 3. Swanson suffered concussion-like symptoms after last week's game against the Tampa Bay Buccaneers, was placed in concussion protocol and didn't practice this week.
In place of Wagner and Swanson, Graham Glasgow will move over from left guard to center and Corey Robinson will step in at right tackle. Joe Dahl will play in place of Glasgow at left guard.
Detroit (7-6) is currently in second place in the AFC North.