Final Word: AFC South

Five nuggets of knowledge about Week 12:

On track: Tennessee Titans running back Chris Johnson said this week he’s not worried about his future with the team, which has to guarantee him an additional $9 million in March in order to keep him for 2013. He averaged just 2.9 yards per carry in his first five games this season, with no touchdowns and just seven runs of 10 yards or more. In his next five games, his average is 6.7 yards, he has four touchdowns and 16 runs of 10 yards or more. He has topped 100 yards in two consecutive games.

Luck data: Indianapolis Colts rookie quarterback Andrew Luck has a .569 completion percentage, 303.6 passing yards per game, eight touchdowns and two interceptions in five home games this season, and the team is 4-1 in those games. He has thrown an interception once every 104.5 attempts when at home but once every 20.3 attempts on the road, per ESPN Stats & Information. Nine of his interceptions have come on throws of more than 10 yards downfield. The Bills have interceptions on five such throws this season, but also have allowed 10 touchdowns. The Colts’ passing yards per game is up from 30th last season to eighth currently and total yards per game is up from 30th last season to fourth currently. Luck’s average pass has traveled 10.3 yards downfield this season, the highest rate in the NFL. Buffalo’s Ryan Fitzpatrick has an average throw distance of 6.9 yards downfield, the second-shortest rate this season.

First start: Chad Henne makes his first start as the Jacksonville Jaguars' quarterback and first in the NFL since Oct. 2, 2011, when he was with the Miami Dolphins. He is one of three active quarterbacks who've lost their past seven starts. The other two are also tied to Jacksonville. Blaine Gabbert is the quarterback Henne is replacing and Byron Leftwich, now of the Pittsburgh Steelers, saw his streak start when he quarterbacked the Jaguars. Henne has not won a game he started since Dec. 12, 2010, for Miami at the Jets.

Also: The Buffalo Bills have given up a touchdown to their opponents on 30.2 percent of their drives this season, the highest rate in the league. The Colts are third at 26.1 percent. … The Bills have been outscored by 72 points in the second half and overtime this season and have given up 48 points off turnovers. … A Colts win would mean Luck ties Sam Bradford (seven in 2010) for most wins by a rookie quarterback selected first overall in the common draft era.… Indianapolis has given up 102 second-quarter points, most in the NFL. … In the Titans' first three road games of the season, they were outscored by an average of 35.3-10.3 and went 0-3. In their past two road games, they have won by an average score of 36.0-18.5 and are 2-0. … The Titans and Jaguars have two of the worst defenses in the NFL. The Titans are the second-worst scoring defense, allowing 31.1 points per game. The Jaguars are allowing 28.9 points per game, fourth worst.

Rooting interests: The Houston Texans won in overtime Thursday in Detroit and have a 10-1 record. There are two scenarios Sunday in which they can clinch a playoff spot: (1) A Titans loss or tie, a Dolphins loss or tie, a Bengals loss and a Chargers loss or tie or (2) a Titans loss or tie, a Dolphins loss or tie, a Bengals loss or tie and a Steelers loss.