Although the Indianapolis Colts have a perfect record, they've been quite vulnerable over the past few weeks, escaping with several close calls.

The Houston Texans have been on the opposite end of the spectrum, losing back-to-back games in agonizing fashion - including once at Indianapolis.

The Colts look to remain undefeated and move closer to locking up a playoff spot Sunday when they visit a Texans team trying to win its first game in a month.

Indianapolis (10-0) holds a three-game lead in the chase for the AFC's top seed and its 19-game winning streak is the second-longest in NFL history behind New England's 21-game run from 2006-08. Nothing, though, has come easy lately for the Colts, who will be without starting defensive end Dwight Freeney after he missed practice all week due to an abdomen injury.

Raheem Brock is expected to start in his place.

Indianapolis, which can clinch the AFC South for the sixth time in seven years with a victory this week coupled with a Jacksonville loss to San Francisco, has won its last four games by a combined 10 points.

In the latest thriller, middle linebacker Gary Brackett picked off Joe Flacco's pass at the Indianapolis 13-yard line with 2:42 remaining to preserve last Sunday's 17-15 victory at Baltimore.

That came a week after Indianapolis scored 14 points in the final 2:23 of a 35-34 victory over New England. The Colts took advantage of Bill Belichick's risky fourth-down gamble, allowing Peyton Manning to hit Reggie Wayne in the end zone for the winning score with 13 seconds left.

On Nov. 8 against Houston, Kris Brown missed a potential tying 42-yard field goal as time expired and the Colts hung on for a 20-17 win.

"We certainly feel we've developed a pretty solid mental toughness," Indianapolis first-year coach Jim Caldwell said. "Hopefully, it's going to serve us down the road and make us continue to get better. Hopefully we can benefit from it."

Houston hasn't had the same luck as Indianapolis.

The Texans (5-5) entered the Nov. 8 matchup riding a three-game winning streak and in the thick of the playoff picture, but they've lost their last two by identical 20-17 scores sandwiched around a bye week.

Similar to the loss to the Colts, Brown missed a potential tying 49-yard attempt with 1 second remaining Monday night against Tennessee.

"We know what kind of capabilities we have, and this is a very young, good football team," said linebacker Brian Cushing, who leads the Texans and all rookies with 88 tackles. "It's just been so disappointing with the way we've lost games, but it happens. We are not going to sulk."

The Texans know they'll probably have to win a majority of their last six games to secure their first playoff berth in eight seasons.

"We just need to win," said receiver Andre Johnson, who had 10 catches for 103 yards against the Colts earlier this month. "That's all that matters. If we win the rest of our games, we get in. If we don't we will be packing our bags at the end of the season again. I don't really think about (playoffs), we just have to win."

Getting a win against Indianapolis might not be that easy, considering the Colts are 14-1 versus the Texans.

Manning, who has topped 3,000 yards for a 12th consecutive season - second to Brett Favre's 17 - has been stellar in those 15 games. The three-time league MVP has thrown for 4,177 yards with 34 touchdowns and six interceptions.

Like the Colts, Houston's offense also relies heavily on the passing game. Matt Schaub, who has a career-best 19 touchdown passes, threw for 305 yards and two TDs last week for his sixth 300-yard game.

With these two strong-armed quarterbacks paired with sputtering ground games, both teams will likely try to move the ball through the air.

The Texans rank 30th in the NFL with 87.4 rushing yards per game, one spot ahead of the Colts (85.0).