The Titans believe that Locker will miss the rest of the season with a Lisfranc injury, a team source told NFL Media's Albert Breer on Sunday.
Locker suffered the injury while handing the ball off to Chris Johnson in the second quarter of Sunday's 29-27 loss to the previously winless Jacksonville Jaguars. Locker wasn't touched on the play. He limped to the locker room and was replaced at quarterback by Ryan Fitzpatrick.
Durability continues to be a major concern for Locker. He missed two games earlier this season after injuring his hip in a Sept. 29 win over the New York Jets. The Titans lost both games Fitzpatrick started.