COLUMBUS - It may be Thursday before No. 4 Ohio State finds out if starting quarterback Craig Krenzel is able to play in the Big Ten opener against Northwestern on Saturday.

Krenzel, who is 18-1 as a starter, missed last week's 24-17 victory over Bowling Green because of a hyperextended right elbow on his throwing arm. He watched from the sidelines in a visor as Scott McMullen directed the Buckeyes' offense.

''I don't know what the plans are,'' Krenzel said, admitting he was frustrated by the injury. ''I don't know how I'm going to feel tomorrow. I don't know if I'm going to be able to throw at all. Ideally I'd like to practice maybe a little bit tomorrow and maybe a little bit on Thursday and then play a little bit on Saturday. But that's down the road and we're kind of taking it day by day.''

Krenzel tossed tennis balls at practice on Monday, then took it easy on his arm by throwing 20 or 30 passes at Tuesday's practice.

''They were real short. I didn't put anything on them,'' the senior said. ''I still haven't thrown any deep routes or anything, so I don't know how it is throwing the ball down the field. I'll wake up tomorrow and see how it feels after throwing for the first time today.''

Coach Jim Tressel said it was too early in the week to tell if Krenzel will be available.

''We'll know by the end of the day Thursday if he'll play significantly, play sparingly, (or) not be able to play at all,'' Tressel said at his weekly news conference on Tuesday.

Krenzel was hurt in the Sept. 13 triple-overtime victory over North Carolina State when his arm was pinched between two tacklers in the second quarter.

Tressel said team doctors would ultimately make the decision whether Krenzel could play. The Buckeyes (4-0) are idle after Saturday's home game against Northwestern before playing at Wisconsin on Oct. 11 in their first road game.

''If the medical people would say to me, he's ready to go, there's no chance of further injury, we're not going to be cautious,'' Tressel said.

Krenzel said he would like to get into a game before the Buckeyes take the week off.

''That's one of the biggest reasons why I'd like to get back out there on Saturday before having a week off,'' he said. ''So when we go to Wisconsin I don't go in not having played in a month.''

McMullen completed 10 of 16 passes for 118 yards and a touchdown, but also threw an interception and lost a fumble.

Tressel said there was a lesson in McMullen's chance at starting.

''Here's a fifth-year senior who has given five years of his life to playing at Ohio State in the shadows, and he got his opportunity to go out there as the starting quarterback at Ohio State,'' Tressel said.

''I think that's a message to any youngster that gets a little bit impatient, that if you keep hanging in there, typically your day or your days will come.''

McMullen's day may very well be at hand.

''It's quite a bit better,'' Krenzel said of his elbow. ''It's not as good as I would like it to be. I threw a little bit today and I was able to throw and that was encouraging. It felt better than I imagined it would. But I still didn't throw great.''

Tressel also said that starting center Alex Stepanovich (sprained ankle) is questionable, backup offensive guard Adam Olds (knee) is probable and that fullback Branden Joe had been cleared to play after recuperating from a torn muscle in his chest.