Panthers place centers Kalil, Gradkowski on injured reserve (Yahoo Sports)

The Carolina Panthers have placed two-time All-Pro center Ryan Kalil and his primary backup Gino Gradkowski on injured reserve, further weakening an offensive line that has been decimated by injuries this season. Carolina signed free agent center Ryan Wendell and offensive tackle Dan France from the Cleveland Browns practice squad on Tuesday to fill out the 53-man roster. Gradkowski recently injured his knee.