One quarterback is a veteran with a steady arm. The other is less experienced, and his scrambling ability gives the offense a different look.

Ohio State's Todd Boeckman and Terrelle Pryor? Yes, them too.

The No. 12 Buckeyes settled on Pryor weeks ago. But now the defense faces a quarterback question, with Northwestern not saying who will lead its offense Saturday.

"I would expect that we would see them both," Ohio State coach Jim Tressel said. "I would expect the (Northwestern) coaches will do the best they can possibly do to utilize both the guys, at whatever mixture they need to have their best opportunity to move the football and score points."

C.J. Bacher is Northwestern's starter, a senior who is among the Big Ten leaders in total offense (third, 243 yards per game) and passing yards (fourth, 212.5). He's led the Wildcats to a 7-2 record, their best in three years.

But with Bacher sidelined last weekend by a hamstring injury, Mike Kafka took over and rallied the Wildcats (3-2 Big Ten) to a 24-17 victory at Minnesota, their first against a ranked team since 2005. The junior rushed for 217 yards, a record for a Big Ten quarterback, and threw for another 143 yards directing Northwestern's spread.

Northwestern coach Pat Fitzgerald said Bacher will start against the Buckeyes (7-2, 4-1) if he's healthy, and Bacher was upgraded to probable after Thursday's practice. But the Wildcats need Kafka's mobility, too, especially after backup running back Omar Conteh was knocked out of this weekend's game with a knee injury.

Leading rusher Tyrell Sutton is already out for the year with a wrist injury.

So who's it going to be? Bacher? Kafka? Both?

"Obviously we'll play to the young men's strengths," Fitzgerald said. "C.J. can run the ball better than people give him credit for, and Mike can throw better than people give him credit for. Both young men are very talented, and give us the opportunity to really run the offense the way that we think we can."

No matter who's under center, he won't have an easy task. Ohio State leads the Big Ten in pass defense, and is third against the run. The Buckeyes have one of the best linebackers in the country in James Laurinaitis, and safety Kurt Coleman and cornerback Malcolm Jenkins have three interceptions each.