It is familiar territory for the Indianapolis Colts, this flirtation with an unbeaten season. But it is entirely uncharted ground for the New Orleans Saints, who spent so much of their history as a beloved but bumbling team, and for the NFL, which is unaccustomed to having two teams still chasing 16-0 records so late in a season.

The Colts and Saints have become the first teams in league history to be 12-0 in the same season, raising the question of whether either -- or both -- can join the New England Patriots of two seasons ago, the only team to go undefeated in a 16-game regular season. The down-the-line target, of course, would be the 1972 Miami Dolphins, who added three postseason victories to their 14-0 regular season.

It is becoming the talk even in opponents' locker rooms. After Tennessee lost Sunday in Indianapolis, Titans linebacker David Thornton was asked in the visitor's locker room at Lucas Oil Stadium if he thought the Colts would go undefeated.

"That's tough to say," Thornton said. "I don't know how they're gonna play their guys. They possibly could. But any team can be beaten."

The issue is far more complex than merely whether a team has the on-field capabilities to win all of its games. It also is a matter of whether a team has the desire to try to win all of its regular season games, and that could become the issue with the Colts.

They're three games ahead of the San Diego Chargers and Cincinnati Bengals, who have 9-3 records, in the race for the top seed in the AFC playoffs and home-field advantage through the conference title game. It seems likely that the Colts will have some games at the end of the regular season that have no postseason implications, and coach Jim Caldwell could sit down key players like quarterback Peyton Manning, wide receiver Reggie Wayne and defensive end Dwight Freeney to avoid injuries that might reduce the team's chances of playoff success.

"If you don't win that big game, it doesn't mean anything," Colts running back Joseph Addai said Sunday. "I think every kid's dream was to try and get to the Super Bowl. Kids dream to play in the Super Bowl. That's the biggest thing. We're trying to get to that point. We do that by winning games. We need to keep on winning games but not try to go undefeated, if that makes sense."

That was the mind-set of Caldwell's predecessor, Tony Dungy, in past seasons. The Colts, under Dungy, were 13-0 in 2005, 9-0 in '06 and 7-0 in '07. Invariably, Dungy talked about chasing a Super Bowl title, something that the Colts got in the 2006 season, and not about chasing history. The refrain sounds much the same now from Caldwell, a Colts assistant since 2002 who took over when Dungy stepped aside after last season.

"Obviously they're going to read about it and be asked about it," Caldwell said this week. "The most important thing is to put yourself in the best position entering the playoffs to win it all."

Manning has not missed a step after also losing his longtime favorite wide receiver, Marvin Harrison, in the offseason. He still has reliable and familiar targets in Wayne, tight end Dallas Clark and Addai, and young wide receivers Pierre Garcon and Austin Collie have become significant contributors. The defense has overcome a series of injuries in the secondary and the Colts have been resilient, winning five consecutive games with fourth-quarter comebacks before Sunday's relatively routine triumph against the Titans.

They'll take a 21-game regular season winning streak, matching the NFL record set by the Patriots between '06 and '08, into today's game at home against the Denver Broncos. For now, postseason home-field advantage is not clinched and the Colts will keep going full speed. It remains to be seen if things will change when they finish the regular season with road games at Jacksonville Dec. 17 and at Buffalo Jan. 3, sandwiched around a home game against the New York Jets Dec. 27.

The Colts clearly don't want to follow the script of the '07 Patriots, whose 18-0 record going into the Super Bowl did them no good when they were upset by the New York Giants.

"We've seen too many teams that go undefeated and toward the end, they really don't make it," Manning said.

Manning was speaking to reporters Sunday as the Saints were completing their improbable comeback victory against the Washington Redskins at FedEx Field. The New Orleans native was asked if he was keeping close tabs on what was happening with his hometown team.

"I care about the Colts," Manning said, but also added of the Saints' prosperity: "It's great for the city down there. I know the fans down there are excited. Drew [Brees] is having a great year. It's good for football."

Sports Illustrated quoted Saints coach Sean Payton this week as saying that he intends to keep his starters in the lineup late in the regular season to take a shot at an unbeaten season and attempt to maintain momentum entering the playoffs.

Two seasons ago, Giants coach Tom Coughlin played his starters in a regular season finale that was without postseason implications for his club. The Giants lost that game to the Patriots, but played well enough to gain confidence and build momentum for the playoffs and won the rematch in the Super Bowl.

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