It's time to jump back into our preseason position rankings with a look at the offensive line units.

On Friday, we ranked the top individual players at the position. These unit rankings reflect star power as well as depth. We're heavily weighing these on last year's performance, along with potential for the 2012 season.

Away we go:

1. Wisconsin: Sure, the Badgers lost two All-Americans (Kevin Zeitler and Peter Konz) from last year's line. But they've earned the benefit of the doubt for their ability to reload up front. Left tackle Ricky Wagner is an Outland Trophy candidate, and center Travis Frederick should be one of the best in the Big Ten. The key will be how the new-look right side with Rob Havenstein and likely Robert Burge moving into starting roles.

2. Michigan: The Wolverines might have the top tackle in the league with junior Taylor Lewan, and guard Patrick Omameh is a three-year starter. Senior Ricky Barnum is taking over for David Molk at center. Michael Schofield should be solid at right tackle, though the left guard spot remains a competition. It should be a strong starting group, though depth here is a major concern.

3. Michigan State: This could be the best offensive line Mark Dantonio has had in East Lansing. Six players who started games last year are back, and there will be depth and competition at several spots. Third-year starter Chris McDonald is one of the league's top guards, while tackles Dan France and Fou Fonoti are dependable.

4. Nebraska: The Cornhuskers lost three starters from last year's line, but much like Wisconsin, this is a group that usually reloads. Guards Spencer Long and Seung Hoon Choi provide nice building blocks, with Tyler Moore, Jeremiah Sirles and Andrew Rodriguez solidifying the tackle spots. The big question here is center and who will replace Mike Caputo.

5. Ohio State: The Buckeyes had their problems up front last year and now are implementing a new offensive system. Urban Meyer wasn't happy with the group's work ethic in January but felt much better about them by the end of spring. Jack Mewhort replaces Mike Adams at left tackle, while Andrew Norwell and Marcus Hall try to live up their potential at guard. Corey Linsley earned Meyer's praise for his work at center. Keep an eye on the right tackle spot, where former tight end Reid Fragel is now the first-stringer. But true freshman Taylor Decker is pushing him.

6. Purdue: Injuries kept the Boilers from building much cohesion this spring, but this can be a sturdy group when healthy. Three starters are back, with Trevor Foy moving from right to left tackle. This is an experienced bunch, but Danny Hope wants to see more dominance. Senior center Rick Schmeig should be a leader

7. Iowa: The Hawkeyes must replace three starters, including NFL draft picks Reilly Reiff and Adam Gettis. But Iowa usually fields good offensive lines, and hopes are high for this year's edition. The leader is center James Ferentz, who now will be coached by his older brother, Brian Ferentz. Much will depend on how players like Brett Van Sloten and Brandon Scherff develop.

8. Northwestern: The Wildcats lost two valuable starters in tackle Al Netter and Ben Burkett but return three-year starter Brian Mulroe at guard and promising sophomore center Brandon Vitabile. There should be good depth up front, but can the Wildcats generate a consistent rushing attack?

9. Penn State: The good news is that the Nittany Lions played better than expected last year on the offensive line. The bad news is four starters are gone, not to mention some potential transfers in the wake of the NCAA sanctions. There is still talent here, including guard John Urschel and tackle Donovan Smith. But the least experienced line in the league will have to learn a new offensive system.

10. Illinois: There was little excuse for the Illini O-line to play as bad as it did last year with standout players Jeff Allen and Graham Pocic in the mix. Pocic is back this year at center, though he might take some snaps at tackle as well. Young players like sophomore Simon Cvijanovic and redshirt freshman Ted Karras will need to come on. This unit should be improved, but it ranks low based on last year's finish.

11. Minnesota: Jerry Kill shuffled this group last year and played a lot of youngsters. It's still a relatively inexperienced unit, but there is hope for improvement. Junior left tackle Ed Olson has the best chance to be a star.

12. Indiana: Center Will Matte is one of the most experienced linemen in the league. But beyond him are several young players, including three true sophomores who started as freshmen last year. There's nowhere to go but up.