Marcus Mariota suffered a fractured right fibula and will miss the rest of the season.

Mariota was carted off in the third quarter with an air cast on his right leg after being sacked from behind by Jaguars DT Sheldon Day.

"We didn't protect him -- offensive line, running backs -- we didn't protect him all day," Titans RB DeMarco Murray said after the game.

Matt Cassel will assume the starting quarterback job for the Tennessee Titans.