Check out the latest in our Big Ten unit power rankings – the offensive line rankings – and look out for more unit rankings every Monday and Thursday.

1. Wisconsin Badgers

Wisconsin returns only two starters from last year’s offensive line, which was one of the best in the Big Ten and one of the best in the country, but Bret Bielema and his staff have become known for producing outstanding offensive linemen.

The Badgers return Ricky Wagner and Travis Frederick, but must replace Josh Oglesby, Kevin Zeitler and Peter Konz.

Wagner could be Bielema’s next star and he will need to do a good job protecting quarterback Danny O’Brien, who will be making his first start at Wisconsin this fall after transferring from Maryland.

2. Iowa Hawkeyes

The loss of first team All-Big Ten left tackle Riley Reiff to the NFL along with two other starters from last season leaves the Hawkeyes with some major holes to fill.

Rising junior Nolan MacMillan is the likely replacement for Reiff at left tackle. MacMillan started six games in 2010 before missing all of last season due to injury. Rising senior Matt Tobin, a 10-game starter last season, should take over at left guard for Adam Gettis, now of the Washington Redskins. James Ferentz, another rising senior, should be amongst the Big Ten’s best at center.

Despite the losses, it would be foolish to think that this group takes a step back in 2012-even with new offensive coordinator Greg Davis installing a new offense.

3. Ohio State Buckeyes

Like Wisconsin and Iowa, Ohio State must make some key replacements on its offensive line, as Mike Brewster, Mike Adams and JB Shugarts are all gone.

However, Andrew Norwell, Marcus Hall and Jack Mewhort all have starting experience and will have more experience protecting quarterback Braxton Miller.

Miller’s speed and coach Urban Meyer’s offense don’t require as much from the offensive line as a typical pro-style offense, but the unit should still be solid and will give Miller ample time to throw.

4. Michigan State Spartans

Rising junior left tackle Dan France and rising sophomore center Travis Jackson form the core of what should be the most reliable O-line in Mark Dantonio’s tenure.

One key loss from last year’s injury-riddled group is guard Joel Foreman, who went undrafted in this year’s draft. Long-time starter Chris McDonald will help to fill the void, along with Fou Fonoti, another player with starting experience.

With the departures of B.J. Cunningham, KeShawn Martin, and Kirk Cousins, the Spartans should rely heavily on their run game-more specifically, potential all-conference honoree Le’Veon Bell. This group will help Bell have a breakout year in 2012.

5. Illinois Fighting Illini

Illinois will be undergoing a lot of change in its first season under new coach Tim Beckman, but the offensive line should be an example of relative consistency, as three starters return.

Jeff Allen and Jack Cornell are gone, but Michael Heitz, Hugh Thornton and Graham Pocic return for the Illini.

Illinois has a mobile quarterback in Nathan Scheelhaase, but the line will have to be stout in order to help break in the new running backs.

6. Michigan Wolverines

The loss of four-year starting center David Molk is a major blow both to this group’s continuity and it’s leadership. Rising junior left tackle Taylor Lewan will make those doubts disappear relatively quickly, his 6-8, 302-lb frame and versatility giving the Wolverines its best O-lineman since Jake Long.

Year two post-RichRod figures to provide a distinct pro-style flavor, moreso than last season, when offensive coordinator Al Borges installed only parts of his new scheme. That means more attack-first run-blocking for rising junior tailback Fitzgerald Touissaint, even with dual-threat quarterback Denard Robinson and his spread-specific skill set.

7. Nebraska Cornhuskers

Nebraska loses three solid linemen in Mike Caputo, Jermarcus Hardick and Marcel Jones, but returns Seung Hoon Choi, Spencer Long and Tyler Moore.

The Cornhuskers had one of the best rushing attacks in the Big Ten last season and they will need to make replacements to continue that success.

The line needs to be good in order to protect quarterback Taylor Martinez, who is inconsistent and has struggled under pressure.

8. Purdue Boilermakers

The Boilermakers lose veteran tackles Dennis Kelly and Nick Mondek, but rising juniors Trevor Foy and Justin Kitchens are reliable replacements. The interior of this O-line should look similar to last year’s, with veteran guard Peters Drey and center Rick Schmeig as the only two true returning starters.

Rising junior Kevin Pamphile and rising senior Schmeig provide depth and versatility, and could find themselves at any spot along the line at some point this season.

Rising senior tailback Akeem Shavers returns from an impressive 2011 campaign, highlighted by a 22-carry, 149-yard performance in the Boilermakers’ 37-32 win over Western Michigan in the Little Caesars Bowl. If this O-line can get its act together before the fall, Shavers could be in for a 1,000+ yard season.

9. Penn State Nittany Lions

Penn State returns just one starter on an offensive line that needs to be very good if the offense wants to be productive.

Matt Stankiewitch returns at center, but after that the cupboard is very bare for the Nittany Lions.

The line will be responsible for protecting quarterback Matt McGloin, who has struggled under pressure –
and just struggled in general – and also for opening up holes for running back Silas Redd. If this unit is below average, Penn State’s offense could be even worse than it was last year.

10. Northwestern Wildcats

Four-year starter Al Netter signed with the 49ers as an undrafted free agent, leaving this O-line with some serious mixing-and-matching to do before the Fall. The early results are murky, at best, as the Wildcats’ D-line exploited this inexperienced group for six sacks and eight tackles for loss in the spring game.

This unit ranked No. 11 in the Big Ten in sacks allowed last season, a metric unlikely to change without Netter and Ben Burkett, another four-year starter.

Fortunately, quarterback Kain Colter has the agility and pocket awareness to evade most pass-rushers, or-at the least-avoid sacks. Offensive coordinator Mick McCall will need to avoid seven-step drops for his first-year starting qb, lest he be subject to the same pressure he saw throughout the spring game.

11. Minnesota Golden Gophers

Minnesota’s offensive line certainly wasn’t its worst unit in 2011, as the Golden Gophers ranked No. 33 in the country in sacks allowed with 1.37 per game.

However, the Minnesota running game was not great last season and the line needs to do a better job in 2012 of opening up holes.

If the line can do a good job protecting quarterback MarQueis Gray, the Gophers’ offense has potential.

12. Indiana Hoosiers

This unit had trouble adjusting to Kevin Wilson’s no-huddle offense last season, one of the main reasons the Hoosiers finished with 0 conference wins. After a full slate of spring practice with rising sophomore quarterback Tre Roberson manning the first-team offense, improvements are to be expected.

At the very least, you can count on veteran center Will Matte to be the one constant amongst this assemblage of inexperienced underclassmen.

Check out the other units in our series: quarterbacks, running backs, wide receivers and teams.