While the San Diego Chargers enter Sunday's AFC divisional playoff game in Denver as nearly double-digit underdogs, they aren't lacking for confidence after getting the best of Peyton Manning's Broncos at Mile High last month.

Coach John Fox's team is out to make sure that doesn't happen again.

Denver had outscored opponents by an average of 20.4 points in winning its first seven home games before falling 27-20 to San Diego on Dec. 12. Ryan Mathews ran for 127 yards and a touchdown while the Chargers (10-7) held the Broncos (13-3) to their lowest point total of the season.

"It's tough to say you're confident knowing what you're going against. You don't want to take that the wrong way," Chargers Pro Bowl safety Eric Weddle said. "Do we believe we can win (again)? Yes. Do we know what a tough challenge it is and how great we have to play? Yeah. It's not just because it's happened in the past it's going to happen. You still have to play at a high level and do the things necessary as a team to win."

"... We have been the underdog all year. We are out to continue to believe in ourselves."

Having averaged 37.9 points during the regular season -- the highest of any team in the Super Bowl era -- the Broncos were held to fewer than 30 in just three games, two of which came against the Chargers. Denver won 28-20 at San Diego in Week 10 behind 330 yards and four touchdowns from Manning.

"It taught us a lesson," tight end Jacob Tamme said of last month's loss. "We did kind of reboot after that and yes, I think we know that we need to play our best ball going forward and that's what we're planning on doing."

While beating the Chargers remains priority No. 1, the Broncos are also eager to prove themselves following last season's divisional round collapse against eventual Super Bowl champion Baltimore. Denver gave up a game-tying 70-yard touchdown with 31 seconds left in regulation before falling 38-35 in double-overtime last Jan. 12 -- exactly a year to the day of Sunday's clash.

"You don't harp on the first time you fell off your bike, but you remember falling off and you know you don't want to do it again," tight end Julius Thomas said. "So, it's not that we're dwelling on the Ravens or even if it's about the Ravens. It could have been any team that we lost to. But we do have a fresh reminder of if you don't come out and play your `A' game in this tournament, you're going to lose."

Coming off a bye, Denver secured the AFC's top seed with a 34-14 win at Oakland in Week 17. The Chargers, meanwhile, won their last four regular-season games to sneak into the playoffs, and they stayed hot with a 27-10 wild-card win at Cincinnati last Sunday.

San Diego ran for a season-high 196 yards while Philip Rivers completed 12 of 16 passes for a season-low 128 yards with a touchdown and no turnovers.

"Going on the road in a playoff game is not going to be easy, regardless of who you're playing," Chargers coach and former Broncos offensive coordinator Mike McCoy said. "We're just worrying about ourselves right now, it's about us, and we're going to keep taking it one week at a time and just keep going, keep plugging away."

The Chargers have run for an average of 170.2 yards during the current five-game win streak and are 10-2 when rushing for more than 102, compared to 0-5 when they don't. It's unclear how much Mathews will be able to contribute, though, after leaving last weekend's game with a lingering ankle injury.

With or without Mathews, San Diego is likely to again turn to its ground game early and often in hopes of keeping Manning off the field. Manning, who set NFL single-season passing records with 5,477 yards and 55 touchdowns, will have his full complement of receivers with Wes Welker set to return.

Welker has been out since suffering a concussion Dec. 8 against Tennessee, his second in a four-game span. Despite his absence, Welker finished second in the league with 18 receptions in the red zone, one behind Chargers running back Danny Woodhead.

"A lot of times teams will decide to go ahead and double Wes," said teammate Demaryius Thomas, who hauled in 14 TD receptions to rank second in the NFL. "So absolutely, it opens up things for me. If I have single-man coverage, it's something that I definitely enjoy and look forward to.

"Wes brings a lot to this offense and we're excited to have him back."

Manning has lost his last three postseason games and is 4-6 in his past 10 overall against the Chargers, including playoff losses during the 2007 and 2008 seasons while with Indianapolis. Rivers has posted a 99.1 quarterback rating in going 6-2 all-time in Denver.

"I've always appreciated and look forward to, as a fan of his growing up, to go against a Peyton Manning-led team," Rivers said. "The teams that we've both been on have had awesome games, and games have come down to the wire, overtime playoff games and our two games this year were really tight.

"They're a No. 1 seed for a reason. This is a heck of a team and it's rare to play an opponent three times in a season and being a division opponent, one we know well, they know us well. It's going to be awesome."