It hardly seems like a fair fight.

There are times when Wisconsin Badgers defensive coordinator Dave Doeren will put on a videotape and watch 264-pound tackle Mike Newkirk take on a double-team of bigger offensive linemen.

No one on the Badgers' defense fights harder than Newkirk, but even the biggest heart can only take a player so far.

"He's one of the tougher guys I've been around," Doeren said. "I'm sure he wishes he were bigger but he is who he is — and we're glad we've got him."

Newkirk represents one of the dilemmas facing UW's defense this season. Since the departure of senior tackle Nick Hayden after last season, the Badgers no longer have a 300-pound anchor inside against power running teams.

The four starters on UW's defensive line average 258.5 pounds. By comparison, last year's starters averaged 275.3 pounds. The starters five years ago averaged 275.8 pounds.

The Badgers have had success in the past with undersized defensive linemen. But this season, every starter is on the smallish side. Senior defensive tackle Jason Chapman (285 pounds) is the biggest starter and he relies on quickness more than strength.

Junior O'Brien Shofield is extremely light for a left end at 232 pounds, while senior Matt Shaughnessy is at best an average-sized right end at 253.

Part of the change has been philosophical. As the Badgers face more spread offenses, they have gone to smaller, quicker defensive linemen.

Part of it has to do with recruiting. Big 300-pounders who play with a motor are hard to find.

"It's give and get," Doeren said of the trade-offs. "We've got quick guys that make plays and (other teams) have got big guys that hold the point and maybe can't make some of the plays that Newkirk makes.

"When you see `Newk' taking on a double team (against) 700 pounds, you'd say, `I wish he weighed 350 right now.' But you see him head fake a guy and he falls down, you're pretty happy he's in there."

While the Badgers' undersized defensive front has held up decently against most spread teams, it was abused in UW's 38-16 loss at Iowa two weeks ago. That's a concern because Saturday the Badgers play at Michigan State, which features possibly the nation's top running back in senior Javon Ringer.

UW, Iowa and Michigan State are the Big Ten Conference's only tailback-oriented, power-running teams. Ringer leads the nation with 300 caries, 1,373 rushing yards and 16 touchdowns.

UW's defensive line was in trouble against Iowa from the opening drive. The Hawkeyes marched 70 yards in seven plays and the only thing that got in their way was the end zone. They finished with 254 rushing yards.

"The game was just terrible," Schofield said. "We weren't playing fundamentally, we didn't have any energy emotionally. ... That's all going to change around. We're back to Wisconsin football."

Defensive line coach Charlie Partridge was in no mood this week to revisit the Iowa game, preferring to focus on the improvement shown in last week's 27-17 victory over Illinois.

"We're happy with the improvement we made from Iowa to last week fundamentally and we're continuing to focus on those fundamentals as we get ready for Michigan State," Partridge said.