Titans quarterback Jake Locker will miss the rest of the season with a right foot injury suffered during Sunday's loss to the Jaguars, coach Mike Munchak confirmed on Monday.
Locker has a Lisfranc injury but it's not clear if he will need surgery.
"I know how depressed he is," Munchak said.
The third-year pro was hurt in the second quarter when he was hit while running for eight yards. He fumbled on the next play then limped to the sideline, where doctors examined him before walking him to the locker room for X-rays.
"I don't know exactly how it happened, but when I got up from that run I could feel it," Locker said on Sunday. "It's tough. You want to be on the football field with your teammates. ... A lot of times your character is tested through adversity and it's up to you to deal with it in the most positive way for yourself and your football team."
Ryan Fitzpatrick takes over as the starter. He had two starts last month after Locker suffered hip and knee injuries in the Sept. 29 game against the Jets.
The ninth-year pro, who has played in four games overall, is 63-of-111 passing (56.8 percent) for 790 yards and four touchdowns. He's thrown four interceptions and has fumbled five times. His passer rating is 76.0.
Fitzpatrick will make his next start when the Titans (4-5) play the Colts (6-3) on Thursday at LP Field. Munchak said Rusty Smith would be the backup.
Locker got off to a hot start as the Titans charged to a 3-1 record. He finishes the season 111-of-183 (60.7) for 1,256 yards, eight touchdowns and an 86.7 rating. He threw four interceptions.
He missed five games last season with a shoulder injury.