The Facts: Mariota suffered a fractured right fibula in Saturday's 38-17 loss to the Jacksonville Jaguars and won't play again this season, the team announced. 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," RB DeMarco Murray said after the game.

Diehards Line: Added HC Mike Mularkey: "It's the first time this season we have been beaten like that. It's a bad time for it. ..." Matt Cassel, the Titans' backup, came on to replace Mariota, who will miss the rest of the season. It's not yet clear if he will need surgery. ... Cassel completed 13 of 24 passes for 124 yards with one touchdown and one interception. The Titans will rally around Cassel, who will either be the QB playing for the AFC South title next week or the guy playing out the string.