Penn State running back Evan Royster, left, is taken down by Iowa defenders Pat Angerer, center, and Karl Klug, right, earlier this season. (Photo: Carolyn Kaster | AP)

Iowa hasn’t allowed a rushing touchdown in 33 quarters, a streak that dates back to the second half of last year’s upset of Penn State, when Derrick Williams scored from the Wildcat formation.

“It’s astounding,” Michigan coach Rich Rodriguez said Tuesday on the Big Ten coaches teleconference. “Normally you think maybe you get a quarterback sneak or something in the goal line that you get in there. But to have 33 straight quarters, an eight- or nine-game span, it’s really quite remarkable.”

The Wolverines, owners of the Big Ten’s second-best rushing offense (197.8 ypg), will try to crack Iowa’s stout defense Saturday (8 p.m., ABC) at Kinnick Stadium.

The Hawkeyes (5-0, 1-0) rank in the middle of the conference in rushing yards allowed, but they’ve been tough in the red zone, allowing just four touchdowns on 10 trips this year.

Iowa coach Kirk Ferentz said the secret to his team’s success really isn’t much of a secret at all.

“One thing we try to do, which most defenses do, is try to make it where it’s at least a challenge for teams to try to run,” Ferentz said. “I don’t think that’s unique in any way, but our guys have done a good job and it’s certainly a positive statistic, so we’re happy about that.”

Rodriguez said Iowa’s strength is a front seven - and particularly a defensive line - that’s playing as well as any in the nation.

Menacing defensive end Adrian Clayborn is among the Big Ten leaders in sacks (three) and forced fumbles (two), high-motor tackle Karl Klug leads the team with 6 ½ tackles for loss, and middle linebacker Pat Angerer is enjoying an all-Big Ten type campaign.

“They’re just very good up front and very aggressive,” Rodriguez said. “They jump the ball well, they get off the ball quick, so it’s a good challenge certainly for our guys. We’ll have to play a lot better than we did this past weekend.”

Michigan’s offense was stymied for the first time this year in last week’s loss to rival Michigan State. The Wolverines (4-1, 1-1) ran for a season-low 28 yards on 28 carries, and didn't score their first touchdown until four minutes remained in the game.

Rodriguez said Tuesday that steps have been taken to recharge his team's running game.

“We’re not certainly going to abandon it,” Rodriguez said. “We’ve got to get better and there’s a lot of things we can clean up, but after watching the film I expected it to be worse as far as some of the things in the run game.

“Even though it wasn’t pretty by any stretch of the imagination, everything we did wrong we think we can fix.”

Dave Birkett covers University of Michigan football for AnnArbor.com. He can be reached by phone at 734-623-2552 or by e-mail at davidbirkett@annarbor.com. Follow him on Twitter @davebirkett.