CENTENNIAL — Why not Arapahoe?

In Friday night's Class 5A quarterfinal in Highlands Ranch between Arapahoe and Valor Christian, the Warriors will enter with an attitude.

Few think the Warriors (10-1) have a chance against the 9-2 Eagles, who won the 2009 3A title, then back-to-back in 4A, and began the 2012 postseason seeded what many perceived as a low No. 4.

"I've heard that this week," Warriors junior tight end Ethan Brunhofer said. "I feel like no one thinks we're going to win."

Having won six straight games, Arapahoe is bidding for its best finish since 1991, when it was runner-up to Cherry Creek (in 6A). The Warriors were a surprising Super 6 League champion and have lost only to 2011 5A winner Columbine.

"The kids have found ways to win," coach Mike Campbell said, noting that they have handled a half-dozen teams that won six or more games. Their strength of schedule, he said, has proved uplifting.

So has quarterback Taven Sparks, who has 1,527 yards passing for 12 touchdowns, including seven to Brunhofer. Running back Jose Cancanon, all the way back from an ankle injury, has rolled to 1,417 yards rushing and 17 touchdowns.

Defensively, the Warriors aren't afraid to employ unconventional formations or use as many as seven defensive backs. Their lack of size up front on offense remains a concern, especially this late in the playoffs, but Campbell has been pleased with the ingenuity and ability to adapt.

The coach realizes they'll need a complete game against Valor Christian, which is on a nine-game winning streak, boasts Colorado's top quarterback-running back duo in Luke Del Rio and Christian McCaffrey, lines that dwarf the Warriors' fronts and a defense that has yet to give up more than one score since Week 2.

"We're going to have to establish some runs, mix it up and create some havoc on defense," Campbell said. "I assume we'll be everybody's favorite, but they've played pretty well."

Eagles coach Brent Vieselmeyer is asked regularly if this group is as good as last year's 4A winner that was undefeated and sported an array of Division I talent. All he's certain about is that "chemistry is our most special thing. They really flow with each other."

Indeed, their target label remains but, "to be honest," Vieselmeyer said, "they just keep talking about today, haven't had one down practice. It's as if they've decided, 'Let's strap it on and go play.' "

And it's exactly what Arapahoe has in mind. Sparks termed it as "exciting."

As for Brunhofer, he said: "There's no place I'd rather be than playing Valor. It's a good feeling."

Neil H. Devlin: 303-954-1714, ndevlin@denverpost.com or twitter.com/neildevlin