CHAMPAIGN - Terry Hoeppner teaches a class in football theory and he has a theory why his Indiana University football team was so awful last week.

"I watched the tape three times, and I'm still shocked and surprised we played the way we did," Hoeppner said this week. "We had mental breakdowns, mental errors and blown coverages. We made too many penalties. We also missed way too many tackles."

No wonder Wisconsin barreled to a 52-0 lead before coasting past the Hoosiers 52-17.

"As painful as it is, you have to analyze it," Hoeppner said. "You have to critique it and come up with answers."

Hoeppner said most of the answers must be found on the defensive side of the ball as Indiana invades Memorial Stadium today. The Hoosiers face a fired-up Illinois team that is celebrating Homecoming while still feeling uplifted by its 23-20 victory at Michigan State last week.

Wisconsin quarterback John Stocco threw just 17 passes against Indiana but completed 15 of them for 304 yards and three touchdowns. Hoeppner said Stocco made it look easy.

"Our pass defense was the most disappointing area," Hoeppner said. "It goes back to Football Theory 101. I teach football theory here and I talk about the phases of football. What's the most important phase? Is it pass offense, pass defense, run offense, run defense or special teams?

"The most important is pass defense, because if you can't play it, any play can be a touchdown play. It also tends to be demoralizing when the ball gets thrown over your head. You just can't give up easy touchdowns."

If Indiana doesn't fix that problem, Illinois and freshman quarterback Juice Williams will be looking to take advantage. Despite starting just two games in his career, Williams already holds the Illini school record for having thrown three touchdown passes of more than 65 yards.

He has touchdown tosses of 76, 69 and 69 yards, and no other quarterback in Illini history has thrown more than two TD passes of that distance.

Indiana is playing a young quarterback, too. Kellen Lewis is a redshirt freshman who is the third quarterback to get a start this season. After also trying Blake Powers and Graeme McFarland, Hoeppner seems to have settled on Lewis, who like Williams is a pass-run threat.

Zook is familiar with Lewis because he played high school ball in Jacksonville, Fla., when Zook was head coach at the University of Florida.

"I remember him when he came out," Zook said. "We looked at him. He's a very good athlete. He's going to get better every time he plays. The added dimension of him being able to run is hard on the defense. The quarterback is not usually the game you prepare for as a runner."

Indiana is last in the Big Ten in rushing offense, averaging just 98.2 yards per game. Illinois, on the other hand, ranks fifth at 178.6 yards per game.

But Indiana fullback Josiah Sears had a career-best 100 yards rushing against Wisconsin.

Indiana's secret weapon might be tiny missile Marcus Thigpen, the fastest player on the team with a 4.29-second 40-yard dash. He already has returned two kickoffs for touchdowns and leads the nation with an average of 38.4 yards per return.

Illinois senior corner Alan Ball said the upperclassmen have tried to keep everyone grounded this week after the heady victory at Michigan State.

"I haven't noticed anything yet," he said when asked if there was a hangover from the Spartan game. "But this week is going to be real big. We have to work just as hard as we have in the past. A lot of guys aren't used to a win.

"It's going to be important for the leaders on this team to remind the young guys what we have to do and where our heads need to be."