COLUMBUS, Ohio – The most potent weapons for No. 20 Michigan and No. 4 Ohio State are undoubtedly their quarterbacks.

Pity their poor defenses in the big showdown on Saturday.

Devin Gardner and Denard Robinson, who may line up everywhere but behind the center because of an arm injury, are the speedsters who lead the Wolverines’ attack. Meanwhile the Buckeyes rely on Braxton Miller, who likes to make tacklers grab handfuls of air when he’s not completing long passes.

Stopping, or at least slowing down, the other team’s quarterback will be the main objective for both defenses.

Good luck with that.

Gardner provided six touchdowns, three running and three passing, in Michigan’s landslide win over Iowa in The Big House last week. Robinson, with 41 touchdowns and 4,273 rushing yards in his career, dabbled at tailback and wide receiver while picking up 98 yards on 13 carries.

Ohio State is in a quandary, having to figure out just how Michigan offensive coordinator Al Borges will use the two. Even he doesn’t seem to know.

“You don’t know – nobody knows – until the lights go on,” Borges said.

So the Buckeyes must prepare for a little bit of everything.

“I just know something’s coming,” Buckeyes head coach Urban Meyer said of the possible sleight of hand. “You just know something’s coming.”

Michigan coach Brady Hoke has been tight-lipped about his plans this week.

The Wolverines refused to even hint at what they might do.

“I never caught a pass in a game before,” Robinson said innocently.

It’s not as if it’s only Ohio State’s defense that has a problem. Far from it. Miller is considered one of the nation’s best quarterbacks and a danger to go all the way every time he touches the ball, even though he’s coming off one of his worst games in an unbeaten season.

Meyer takes the blame for that. He said he buttoned up the offense and leaned on the defense when the Buckeyes took a 14-0 lead at Wisconsin last week. As a result, Ohio State foundered when they had the ball throughout the second half.

Wisconsin came back to force overtime, but the Buckeyes scored easily and then held for a 21-14 victory.

“I take (the) fault,” Meyer said. “I was very conservative in the second half of that ballgame. We have to open it up a little bit and we’re going to do that this week.”

Despite the speed he has at the skill positions, Hoke didn’t have anybody to play the role of Miller during practice this week.

“I don’t think we can ever find a guy that can give us the look that you’re going to get from Braxton, his athleticism and the maturity,” he said. “That’s something that’s hard to find when you’re trying to replicate that. The other part about it is he’s surrounded by a great cast.”

A year ago as a callow freshman, Miller almost led an Ohio State team that would finish with a 6-7 record to victory at Michigan. An underthrown pass to a wide-open receiver streaking down the sidelines would have given the Buckeyes the lead in the final minutes of what would be a 40-34 defeat.

Miller still isn’t mistaken for Peyton Manning, but he is a much improved passer. On top of that, he’s got speed to spare when he turns on the afterburners as he’s leaving the pocket on a scramble.

“He’s throwing the ball better, he’s very elusive,” Michigan defensive coordinator Greg Mattison said. “He’ll take off running full speed, and he’ll stop on a dime. He looks stronger. I thought he was good last time. He’s a very, very good quarterback.”

And he’s not alone out there. The Buckeyes may not have another quarterback with him, but they have tailback Carlos Hyde, with 824 rushing yards and 15 touchdowns, and several other threats to spread the workload in Meyer’s hurry-up attack.

“It’s a significantly different offense,” Michigan safety Jordan Kovacs said. “It’s an up-tempo offense that can run the ball downhill and they have a lot of athletes that they like to get the ball to in space. This year, they put a little bit more speed on the field.”

As the defenses know, that last statement is true for both teams.