Marcus Mariota suffered a fractured fibula in the third quarter of Saturday's loss to the Jacksonville Jaguars, coach Mike Mularkey told reporters. He is out for the remainder of the season
The Tennessee Titans quarterback had an air cast placed on his right leg after his foot was bent awkwardly on a sack by Jags defensive lineman Sheldon Day.
Mariota was carted off the field and immediately ruled out. Matt Cassel took over under center.
Mariota struggled before the injury, completing 8 of 20 passes for 99 yards and a touchdown.