COLUMBUS, Ohio -- Even if he's eligible, Maurice Clarett may be unable to play in Ohio State's opener if he doesn't return to practice soon.

Buckeyes coach Jim Tressel said Saturday that his star running back might not be in good enough shape to play Aug. 30 against Washington. Clarett is being held out of preseason workouts while he is investigated by an Ohio State committee and the NCAA.

The 10-person university committee is looking into allegations of preferential treatment for Clarett and other athletes in the classroom, while the NCAA is investigating an exaggerated police report that Clarett gave to campus police after his car was burglarized in April.

"I would think that everyone who is going to play significantly in a ballgame like that has to be prepared physically," Tressel said. "That's why you have preseason, to get guys ready so that when they go out there healthwise it's the best thing for them. I get nervous about a lot of the guys who maybe haven't had as much work as we like."

Clarett, banned from all team activities, has been working out on his own. Tressel said it was unlikely that any player could be in game condition after spending only a handful of days working out with the team.

"It would be real hard. Real hard," he said.

Tressel said there was no substitute for contact and game conditions.

"Football is football. Running and lifting is the closest thing we can get to it, but it's not football," he said.

He said it was not possible for a player to be physically ready for a game without working out with the team.

Clarett is considered one of the top Heisman Trophy candidates after rushing for 1,237 yards and scoring 18 touchdowns a year ago as the Buckeyes went 14-0 and won the national championship.

Earlier Saturday, the Buckeyes were ranked No. 2 in the preseason Associated Press poll.

Clarett's two replacements are nursing injuries. Maurice Hall, who has a bum right knee, saw some action during a scrimmage Saturday, while Lydell Ross sat out with a pulled quadriceps muscle.

Hall said his knee was sound but that he and team doctors were trying to be cautious by limiting his playing time. If Clarett is not available, Hall said he felt he and Ross were up to the challenge of replacing one of the top players in the country.

"Regardless of whether (Clarett) is here or not, they're always going to depend on the running backs - whoever it is - to carry the load," Hall said. "So, if he's here, they're going to depend on us although maybe not as much. If he's not here then, they'll depend on us a little more. We've got to be prepared for that -- and we are."

Freshmen and walk-ons saw most of the activity. The Buckeyes ran roughly 100 plays on the steamy day.