Titans QB Marcus Mariota carted off field with ankle injury

Titans quarterback Marcus Mariota was carted off the field with an air cast on his right ankle in the third quarter of Tennessee's game against the Jaguars. 

Mariota was sacked by Jaguars defensive lineman Sheldon Day before going down with the injury, and the team immediately ruled him out from returning.

The Titans were losing 25–10 when Matt Cassell took over as quarterback. He threw a touchdown in the fourth quarter to make it 25–17.

Mariota, 23, has thrown for 3,426 yards and 26 touchdowns through 15 games this season.

Tennessee was tied with the Houston Texans at 8–6 and in first place in the AFC South going into Saturday. A Titans loss would allow the Texans to clinch the AFC South with a win over the injury-stricken Bengals on Saturday night.