Iowa State's 13-2 start has been a surprise to those who thought the rebuilding program couldn't win that many games all year.

Now comes the Big 12 — the true test for the surging Cyclones.

Iowa State takes a seven-game winning streak and concerns about depth into Saturday's conference opener at Nebraska (12-2), which is on its own surprising roll.

The Cyclones played just six guys for nearly all 40 minutes of a 72-63 win over Northern Illinois on Monday night. Guard Scott Christopherson, the team's second-leading scorer at 15.1 points per game, sat out with a bruised shooting elbow and freshman center Jordan Railey was held out for the first of a two-game suspension for violating team rules.

With four transfers not eligible until 2011-12 and guard DeMarcus Phillips' sudden departure last week, first-year coach Fred Hoiberg added a pair of football team walk-ons Monday, just to have enough bodies to practice without wearing his guys out.

"We're playing against grown men now every night. Each and every night," Hoiberg said. "I'd love to be able to do toughness drills in practice, but with our limited bodies it's just hard to do. You just try to prepare them mentally and try to save their legs as much as you can."

Can an eight-man rotation work for Iowa State through the grinding Big 12 schedule? Well, everyone in it has exceeded expectations so far.

It all starts with point guard Diante Garrett, who has fulfilled the promise Hoiberg saw in him when he made the senior the focus of the offense. Garrett is averaging 17 points per game, nearly eight better than he had a year ago, and his six assists per night lead the Big 12.

Christopherson fought through a series of injuries in 2009-10. But he's been healthy and productive nearly all season and is expected to play Saturday. Christopherson has blossomed into one of the league's best shooting guards at 51.7 percent from 3-point range.

Freshman Melvin Ejim has solidified the small forward spot. At 6-foot-5 and a solid 215 pounds, he has shown versatility with 12.7 points and 7.2 rebounds per game. He shoots an unfreshman-like 70 percent from the free throw line.

Whether Iowa State will have enough bodies in the paint will likely determine how far they'll go in the Big 12.

Forward/center Jamie Vanderbeken leads the league in blocks, but he's more of a perimeter player who plays low out of necessity. Freshman forward Calvin Godfrey is a talented but still developing player, and Railey is still more of a long-term project than a short-term solution.

The third freshman of the group, 6-foot-9 Eric McKnight, hasn't had much playing time. He spent most of Monday night's win on the bench with walk-ons Andrew Mitchell and Austin McBeth, both on the team less than 24 hours.

But the Cyclones wouldn't be where they are without surprise contributions from unlikely sources.

Six-foot-two guard Jake Anderson leads the team with more than eight rebounds a game, many of them long defensive boards that allow Iowa State to get into a transition game that's been effective.

"He's just beyond my wildest expectations," Hoiberg said. "What he's delivered to this team, as far as his leadership, his passion, his toughness, his rebounding. He just gives you whatever you need."