Big Ten power rankings

Posted by ESPN.com's Adam Rittenberg

A bit of shuffling this week despite three teams -- Wisconsin, Illinois and Michigan -- that had byes. There's still a lot of mystery after the top three or four squads, and we'll know much more in five days as league play finally begins.

1. Wisconsin -- The bye week came at a good time for the Badgers, who are still dealing with some key injuries (Travis Beckum, Jonathan Casillas, Aaron Henry). It might sound wacky, but Saturday's game at 1-2 Michigan could be a trap game for Wisconsin, which can't look ahead to mega matchups with Ohio State and Penn State the next two weeks at Camp Randall Stadium.

2. Penn State -- The Lions beat Temple 45-3 and called their performance sloppy. Impressive is a better term to describe a team that has capitalized on weak competition and looked great on both sides of the ball. Penn State finally gets a test this week as Illinois visits Happy Valley. Another convincing win could give the Lions the top spot.

3. Ohio State -- The Terrelle Pryor era is under way in Columbus, and the freshman turned in a record-setting performance in his first career start. But the Buckeyes once again didn't look impressive against an inferior opponent, and they'll have to be much better in league play to reclaim the top spot in the rankings.

4. Michigan State -- It's a little unfair to drop Illinois after a bye week, but the Illini don't look like an improved team, while Michigan State does. Running back Javon Ringer has been the Big Ten MVP through the first four games, and the defense is displaying the physical style that head coach Mark Dantonio demands.

5. Illinois -- The good news for the idle Illini is they have a chance to make a huge statement Saturday at Penn State and vault up the list. The offense and defense rarely have played well at the same time, and Illinois will need both units to be clicking in Happy Valley. A veteran defensive front seven faces a huge test in the Spread HD offense, and Juice Williams tries to replicate his big-game road heroics.

6. Northwestern -- At this point in the season, the Wildcats are usually lamenting a bad nonleague loss and a leaky defense. Instead, they find themselves 4-0, thanks to a dominating defense shaped by coordinator Mike Hankwitz. The offense has been the problem so far, and Northwestern will need a lot of improvement from senior quarterback C.J. Bacher to keep this spot.

7. Iowa -- The Hawkeyes have found a running back (Shonn Greene) and several young playmakers on defense, but football still comes down to the quarterback position, and Iowa remains a mystery there. It seems like whoever comes off the bench -- Jake Christensen or Ricky Stanzi -- outplays the starter. Coach Kirk Ferentz might need to just pick a guy already because the rotation isn't working.

8. Purdue -- Staring straight at another crushing loss, the Boilermakers came up big against a solid Central Michigan team. Senior running back Kory Sheets continued to show he can handle the featured role by rushing for the game-winning touchdown. Purdue's playmaking secondary has become one of the team's strengths. A road win against Notre Dame would move the Boilers higher.

9. Minnesota -- I kept the Gophers in the basement after three wins, but a 37-3 win against Florida Atlantic made me a believer. Coordinator Ted Roof has ignited the nation's worst defense in 2007, as an influx of junior college transfers and several holdovers have meshed so far. Minnesota is forcing turnovers on defense and limiting mistakes on offense. Quarterback Adam Weber has been fabulous so far.

10. Michigan -- I'll be surprised if the Wolverines end up here at the end of the season, but it might be awhile before they move up. Wisconsin and Illinois visit the Big House the next two weeks, and Michigan needs an upset to keep its bowl hopes alive. A defense that struggled against Notre Dame must step against Wisconsin's power run game, and both Steven Threet and Sam McGuffie need to take another step forward.

11. Indiana -- Saturday marked the first chance for us to learn something about Indiana, and it wasn't promising. Two cupcake games didn't prepare the Hoosiers for a formidable Ball State team. Indiana's defensive front couldn't stop MiQuale Lewis, and Hoosiers quarterback Kellen Lewis had a rough night throwing the ball. The Hoosiers have a chance to move up by beating Michigan State at home on Saturday, but they deserved to drop.