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 and will undergo surgery in the coming days.
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. The Titans quarterback couldn't connect deep and was off target early as Tennessee dug itself a big hole.