Going into a tough game against Oklahoma this week, Air Force is holding its breath on a hand injury to fullback Jared Tew.

Tew, a first-team preseason all-Mountain West pick who rushed for 970 yards last year, is still undergoing tests, but he might have a broken bone in the back of his hand.

“Possibly,” Air Force coach Troy Calhoun said Sunday.

Nathan Walker, who scored Air Force’s final touchdown against BYU and is a Colorado Springs Christian School product, would start in Tew’s place. Ryan Southworth would be the backup fullback. Because of ball-security issues, Calhoun said it would be unlikely Tew would play with the injury, even with a cast.

“I think that would be a stretch, if it’s indeed broken,” Calhoun said.

If Tew is out for a while, at least the Falcons have an experienced backup. Walker is a senior, and had 218 yards on 42 carries last year.

“He’s solid,” Calhoun said. “He’s a good back in what we do.”

A day after beating BYU, Calhoun still wasn’t in a mood to celebrate. Instead of basking in the team’s 2-0 start, including a win over the Cougars for the first time since 2003, Calhoun was still worried about some mistakes the team made.

“We have to get back to doing Air Force stuff well,” Calhoun said. “I saw good effort, and yet, we have to make a lot of progress.”

Part of the reason Calhoun can’t rest is the Falcons play No. 7 Oklahoma.

Air Force is on the verge of getting in the Top 25. The Falcons were the third team in “others receiving votes” outside of the top 25 in the AP poll, and fourth team outside of the top 25 in the coaches’ poll.

Air Force will be underdogs this week, but it looks forward to the challenge.

“We’re the Air Force and we’re going to be smaller than some people and not as fast as some people, but going against a big school like that and showing how we play says a lot to the country, and to us,” safety Jon Davis said.