16 Matt Cassel QB

Cassel suffered a thumb injury that will require surgery, but he is expected to be ready for training camp.

The veteran signal caller will have a pin inserted into his throwing thumb after injuring it earlier in the week. Fortunately, the timeframe for his return lines up with the start of training camp, so it's expected that he won't miss any time beyond the remainder of OTAs. Once healthy, Cassel figures to assume the backup role behind Marcus Mariota. The Titans are not expected to add another quarterback for depth in Cassel's absence.

Cassel signed a contract extension with the Titans on Thursday, Ian Rapoport of NFL Network reports.

Securing Cassel for the next year was one of Tennessee's main priorities entering this offseason. The extension will keep the veteran quarterback as the Titans' backup for the 2017 campaign. Marcus Mariota broke his right fibula in Week 16, pushing Cassel into the starting quarterback role. In his only start of the season, he completed 16-of-26 passes for 150 yards, one touchdown and one interception. While Mariota is making steady progress in his recovery, it is very possible that Cassel could see starting reps during training camp and into the preseason.

Cassel completed 16 of 26 passes for 150 yards with one touchdown and one interception in Sunday's 24-17 win over Houston.

Cassel wasn't very impressive filling in for Marcus Mariota (leg), but did enough to win his lone start of the season. Most of his damage came courtesy of wide receiver Rishard Matthews, who had nine catches for 114 yards and a touchdown. The unrestricted free agent will likely land a backup role somewhere else this offseason.

Cassel will start next Sunday's game against the Texans due to Marcus Mariota's season-ending broken fibula.

Mariota's right leg was injured during a third-quarter sack Sunday in Jacksonville, requiring an air cast and a cart to make sure he reached the locker room without further aggravation. Directing the offense thereafter was Cassel, who completed 13 of 24 passes for 124 yards, one touchdown, and one interception. The Titans' playoff hopes now hinge on results elsewhere in the division in Week 16, but if they're alive on Jan. 1, the veteran signal-caller will seek out the franchise's first visit to the postseason since 2008.

Cassel completed his lone passing attempt for 10 yards, and added a two-yard run in Thursday's 36-22 win over the Jaguars.

Cassel got some mop-up duty with the Titans nursing a 36-8 lead inside four minutes to play in the fourth. With Marcus Mariota heating up of late, the veteran backup won't see any meaningful playing time unless the second-year starter gets hurt.