Never mind that Ohio State last week became just the fifth major-college school to win 800 football games, is tied with Southern California for the best record in the nation the last three-plus seasons (35-5) and reached the last two BCS National Championship games.

When the fifth-ranked Buckeyes take on No. 1 USC on Saturday at the Los Angeles Coliseum, they will be playing for credibility among the elite — not only for themselves but also the Big Ten itself as Michigan sags in the background.

It's not just that OSU trailed Ohio 14-12 in the fourth quarter last week before rallying to win 26-14 with just 272 total yards against the Bobcats, projected sixth in their division in the Mid-American Conference.

"We survived, I guess," coach Jim Tressel said in a teleconference.

It's not simply that Ohio State was jackhammered by Southeastern Conference foes in its past two title game appearances, first being run dizzy by Florida 41-14 in 2007 and then run over by Louisiana State 38-24, fueling perception that the best of the Big Ten was a lumbering lot.

"Those match-ups, you know, just didn't go their way," USC coach Pete Carroll said during his weekly news conference.

And it's not merely because USC has beaten the past seven Big Ten foes it has faced by an average margin of 28 points and appears no less daunting this season after opening with a 52-7 win at Virginia.

But put it all together, and small wonder the Buckeyes are double-digit underdogs.

"It doesn't sound wonderful, but, really, what people think is not that important to me," Tressel said. "Now, the guys in the locker room, what they're thinking is key."

As for what he's thinking about their thinking?

"I think every experience you have, you can take something from it and you can build on it," he said. "I'd rather build on improvement than I would build on not doing as well as we could, because the bottom line is this: "The only way we can be successful on the road at Southern Cal is to be at our best. I mean, there's no way that we can do it if we're not at our best."

The Buckeyes had hoped to be closer to their best with the return of tailback Chris Wells, who suffered a toe injury in the opener against Youngstown State and missed the Ohio game. He told Tressel he's ready to run 45 times against USC, but the coach said it was doubtful Wells would play. Wells rushed for 1,609 yards last season and entered the season considered a Heisman Trophy contender.

Whatever the result, the game represents an increasing rarity in college football — a nonconference regular-season matchup of traditional juggernauts risking their national title aspirations.

Each is an iconic presence in college football, decorated with multiple national championships, seven Heisman Trophy winners apiece and the distinctive uniforms and traditions that are much of what make college football special.

"The great heritage that they have that lives through those players and those famous names that we grew up watching ... just like USC, they hold very dear to their heart," said Carroll, once an assistant at Ohio State. "There's a lot of similarities."

Just not between the coaches, who are almost caricatured representations of their parts of the country — Carroll, the flamboyant Californian and Tressel, the sweater-vested, close-to-the-chest Midwesterner.

"I can't compare," Carroll said, playfully. "He does what he does. He's from Akron. We're from San Francisco."

As for how similar the current programs are, Saturday will tell much.