The Rich Rodriguez era in Michigan was defined by an explosive offense and an inept defense that led to his dismissal.
In 2010, the Wolverines defense hit rock-bottom. They gave up 35 points a game and needless to say, they couldn't stop anybody from scoring on them. This led to many unnecessary losses.
When Brady Hoke was chosen to be the head coach of the Michigan Wolverines in January 2011, he hired his friend Greg Mattison. As many people know, Mattison was the defensive coordinator of the famed Baltimore Ravens defense.
With the combined efforts of Hoke and Mattison, the Wolverines defense once again became respectable, giving up just 17 points per game. Michigan's win/loss record reflected their much-improved defense, as they went 11-2 and won the Sugar Bowl.
But that was 2011. How will year two go in Greg Mattison's defense? How will Michigan replace some key departures on the defensive line?
One of the first changes Greg Mattison made when he came to Michigan was alter the defensive structure from a 3-3-5 to a 4-3. This led to immediate success, with more men able to plug the line of scrimmage from shifty running backs.
The biggest question this team faces from a defensive standpoint is the defensive line. Why? Well, DTs Mike Martin and Will Heininger have graduated, along with DE Ryan Van Bergen. So three out of the four starters on the line of scrimmage have departed, with only DE Craig Roh returning.
So who are the most likely candidates to replace those three starters? One man should be the individual in the picture above, DT Will Campbell.
Campbell, the Rivals and Scout.com 5-star recruit out of Cass Tech High School in Detroit, hasn't lived up to the great expectations many have put on him so far. Perhaps this is the year Campbell finally lives up to his potential and terrorizes offensive centers and guards.
So who will the other defensive tackle be?
Look no further than incoming freshman Ondre Pipkins.
Pipkins, the 5-star Rivals and 4-star Scout.com phenom out of Missouri, was an absolute superstar in the 2012 Army All-American game. Because Michigan lacks sufficient depth on the defensive line, he can (and most likely will) be starting this fall.
So who's going to be the other DE alongside Craig Roh? The top candidate in my mind is junior Jibreel Black so I'm going to be selecting him.
Projected Starters: DE Craig Roh, DT Will Campbell, DT Ondre Pipkins, DE Jibreel Black
Despite the defensive line being thin from a depth standpoint, the linebackers are extremely deep, with many bodies able to play in case of injury.
Kenny Demens is going to be a senior this season, so it will be his last as a Michigan Wolverine. Demens posted 94 tackles in 2011 and looks to continue being a tackling machine. If he can stay out of legal trouble, Kenny can look forward to the 2013 NFL Draft with a positive outlook.
Jake Ryan (pictured above) was a key standout at last year's spring ballgame, intercepting a Denard Robinson pass and returning it for a touchdown. This season, he's going to be just a redshirt sophomore, and with a year under his belt, he's only going to get better under Hoke and Mattison's tutelage.
The final linebacker position is a bit more difficult to see who's going to be starting. RS junior Cam Gordon was supposed to start all last season but fell to numerous injuries. Will he be able to recover?
Sophomore Frank Clark had a key interception in the Sugar Bowl against Virginia Tech in limited action.
But Desmond Morgan took full advantage of his extended playing time as a freshman and should compete against Cam Gordon for the final linebacker position.
Spring ball is going to be very fun to watch this year.
Projected Starters: ILB Kenny Demens, OLB Jake Ryan, OLB Cam Gordon
As a true freshman, Blake Countess worked his way into the starting cornerback position for the Michigan Wolverines alongside J.T. Floyd.
Countess was high on Rivals' and Scout's rankings, hitting 4-stars, while ESPN ranked him the 14th best cornerback in the country.
In limited playing time, Countess had 30 solo tackles and 14 assists for a total of 44 tackles. He's only going to get better as a sophomore.
J.T. Floyd will be a senior this year and should also put up solid statistics against the pass and the run alike.
Safety Jordan Kovacs will be a RS senior this year, while RS junior Thomas Gordon will start at the other safety position. Mattison would sometimes blitz Kovacs to throw off opposing offenses and it worked to perfection, as Jordan had four sacks last season to go with his 75 tackles.
So there's not going to be any position changes of note here.
Projected Starters: CB J.T. Floyd, CB Blake Countess, S Jordan Kovacs, S Thomas Gordon
As we've seen, Michigan has very little to replace on the defensive side of the football.
The cornerback and safety positions should stay with the same players, and only one linebacker position needs to be filled, but with the depth that the linebackers have, there's all kinds of players that should fit in nicely for the lone open spot.
And again, the defensive line is the major issue that will need to get worked out so the three starters can be named before the start of the season in Texas.
If Hoke and Mattison can find those answers quickly and efficiently, the Wolverines will pick up where they left off last year. And that won't be good news for the rest of the Big Ten.