Michigan fans have to be thrilled with their OT upset win against Northwestern, despite not having Denard Robinson under center.

But if the Wolverines want to break into the national championship contender level, they need to do something about that defense.

Michigan gave up 241 yards rushing and 431 yards of total offense to the Wildcats today, not to mention 31 points. The Wolverines had the firepower to run with that today even without Robinson, but that's not going to fly against the better offenses in the nation. 

And whether or not Robinson is back, the defense is going to need to step up in a big way if the Wolverines want to beat hated rival Ohio State.

True, Michigan has the No. 13 scoring offense in the nation right now. However, most of the teams Michigan has faced so far have suspect offenses. 

Those teams that have solid offenses like Alabama, Nebraska and now Northwestern have had little trouble scoring on the Wolverines. The Crimson Tide scored 41 points, the Cornhuskers got 23, and now the Wildcats had 31.

Jesse Johnson-US PRESSWIRE

Ohio State has a solid offense as they are No. 12 in the nation in scoring offense. That could spell trouble for the Wolverines.

Michigan has so many pieces needed for a championship team. They've got solid coaching in Brady Hoke and a solid quarterback in Denard "Shoelace" Robinson.

But, as they say, defense wins championships.

Michigan is doing well with the team they have now, but if they want to play for B1G and national titles, that defense must step up.