ANN ARBOR, Mich. (AP) -- All season, Michigan has been able to count on its defense.
After Saturday's 38-31 overtime win over Northwestern, the 23rd-ranked Wolverines can't even be sure about that.
The Wildcats put up 431 yards against Michigan, and should have won the game in regulation if not for a bad punt and a spectacular pass from Devin Gardner to Roy Roundtree.
"We didn't tackle as well as we wanted, and we didn't get off blocks on the perimeter as well as we needed," coach Brady Hoke said Monday. "We did some good things inside, and took away that part of their running attack, but we let things go too much outside."
Quarterback Kain Colter and tailback Venric Mark combined for 186 yards as Northwestern's option gave Michigan problems all game.
"You have to give those two a lot of the credit," Hoke said. "Colter is a great football player, and Venric Mark could play anywhere in the country, but we have to be able to do a better job of containing them."
Senior defensive lineman Will Campbell agreed that being unable to stop Colter was Michigan's biggest problem.
"We couldn't contain their quarterback, and that really hurt us," he said. "We needed to do a better job of getting him inside."
Of course, at the end of the game, Michigan's defense held in two key situations. They forced Northwestern to punt with 28 seconds left, then stopped the Wildcats on downs in overtime.
"At the end of the regulation, we knew we had to get a stop right there or the game was over," Campbell said. "We got the stop, and then I looked at Devin coming onto the field, and I knew we had a chance."
Gardner's pass to Roundtree gave the defense another chance in overtime, and this time they stopped Northwestern on 4th-and-2 to end the game. The Wildcats went to the option that had worked so well all game, but Kenny Demens stopped Tyris Jones for no game.
"We had Jordan Kovacs all over the pitch, so they couldn't get the ball to Mark, and we had two guys on the quarterback, so they had to run it inside," Hoke said. "That left it up to Demens, and he made a great play to wrap the guy up and end the game."
Michigan will be facing an entirely different kind of attack Saturday in Iowa's pro-style power-running system, but Craig Roh doesn't think that makes much of a difference.
"They are different, but at the end of the day, it all comes down to getting off blocks and making plays," he said.
"That's the case no matter what kind of system you are going against."
Michigan also doesn't know who will be playing quarterback against the Hawkeyes, or if they do, they aren't saying. Denard Robinson has missed the last two games with nerve damage in his elbow, and Hoke wasn't giving any hints.
"He's day-to-day," he said, repeatedly.