NASHVILLE, Tenn. (AP) The Houston Texans know exactly what's on the line Sunday in Tennessee.

Oh sure, sweeping their AFC South rival for a second straight season would be a nice bit of franchise history. Clinching a divisional title and playoff berth matters much more.

''This would be huge,'' Texans linebacker Brian Cushing said. ''We know what's at stake, so we just have to take care of business.''

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The Texans (7-7) took a big step toward what would be their third AFC South title last week with a 16-10 win in Indianapolis - their first ever in Indy. Now they can clinch that championship, with the easiest scenario a Houston win and a Colts loss or tie in Miami. Beating the Titans also would ensure the Texans finishing no worse than .500.

''The importance of these games is huge,'' Texans coach Bill O'Brien said. ''Our players understand that. We understand that it's going to be a very, very tough game, a division game on the road. It's going to be a big challenge for us.''

The Titans (3-11) will be without rookie quarterback Marcus Mariota in their home finale after he sprained his right knee in their 33-16 loss at New England, so backup Zach Mettenberger will start for the fourth time against Houston in his two seasons. A win would allow them to finish a woeful season with two straight victories at home. Spoiling the Texans' playoff designs would be a sweet bonus.

''We're trying to win a game,'' Titans right guard Chance Warmack said. ''It would be great to knock them out of the playoffs; I'm not going to sit up here and lie to you.''

Here are some other things to watch for Sunday between the Texans and Titans:

QUARTERBACK CAROUSEL: Brandon Weeden could become Houston's fourth starting quarterback this season if Brian Hoyer can't play. Weeden made his debut with the Texans in Indianapolis after T.J. Yates tore his ACL. Now he's in line to start with Hoyer still recovering from his second concussion in less than a month. Hoyer returned to practice on a limited basis, but remained in the concussion protocol.

If Hoyer is inactive, then B.J. Daniels, signed off Seattle's practice squad on Monday, will back up Weeden, who was signed Nov. 19 after being released by the Cowboys two days earlier. Weeden believes he'll feel much more comfortable if he has to play this week after getting more than a half of work against the Colts.

WHAT A PAIR: Houston defensive end J.J. Watt is tied for second in the NFL with 13 1/2 sacks and outside linebacker Whitney Mercilus has a career-best 8 1/2. If Mercilus gets at least 1 1/2 sacks in the last two games, it will give the Texans two players with 10 or more sacks for the first time in franchise history. Mercilus had the best game of his career in Houston's 20-6 win over Tennessee on Nov. 1 with 3 1/2 sacks.

PROTECT QB BETTER: Ken Whisenhunt was fired as Titans coach two days after the Texans beat Tennessee 20-6 on Nov. 1, a game when Mettenberger was sacked seven times and hit seven others. Mularkey has shuffled his starters on the offensive line and done his best to keep his quarterbacks upright. Another change is coming Sunday after the Titans gave up five sacks in each of the past two losses. Joe Looney will start for rookie center Andy Gallik, his second start at that spot.

WRIGHT'S BACK: Titans wide receiver Kendall Wright is expected back after missing two games with two broken ribs. Tight end Delanie Walker said having Wright back will ease the defensive pressure on himself and rookie receiver Dorial Green-Beckham.

CLOWNEY'S CLIMB: Houston outside linebacker Jadeveon Clowney has put the injury-filled start to his career behind him and finally is starting to show why the Texans drafted him first overall in 2014. Clowney has 3 1/2 sacks in the last five games and eight quarterback hits and eight tackles for losses this season. Clowney has started to draw double teams normally reserved for Watt and also has been key in Houston's improvement against the run.

''It looks like Clowney is probably as healthy as he has been, and he is a force to be reckoned with,'' Mularkey said.

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AP Sports Writer Kristie Rieken contributed to this report.

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Follow Teresa M. Walker at www.twitter.com/teresamwalker