"It's a lot of fun. Game day, that's the best day of the week for me. We're just really looking forward to the challenge. I mean, 19 [wins] in a row, No. 4 team in the country, we realize that it's a huge, huge challenge. But we look forward to it."
The Buckeyes (7-0, 3-0 Big Ten) enter Saturday night's game on their home field having won all 19 games in which Urban Meyer has been their head coach. They rallied from halftime deficits in each of their last two wins, over Northwestern and Iowa, because of the confidence the coaches and players have in making adjustments throughout the streak, O'Brien said.
The wins have kept coming this season for other reasons, and O'Brien thinks two of them are quarterback Braxton Miller and the Ohio State defense.
"He's just doing a really, really good job of running that offense in all facets of that offense," the coach said of Miller. "It's a very difficult challenge. You don't win 19 games in a row or you don't get to 7-0, No. 4 in the country, without being an excellent quarterback, and that's what he is."
He gave similar kudos to the defense led by linebacker Ryan Shazier, who returned an interception for a touchdown in last year's Buckeyes win at Beaver Stadium, and cornerback Bradley Roby.
"Then obviously there's a lot of other guys on that defense that are playing well, too," he said. "You don't get to 7-0 without having a good defense, and they have a very, very good defense."
The Nittany Lions (4-2, 1-1) are coming off their second bye week of the season. O'Brien said his primary goal last week was to get his players healthy. The team practiced only two days before resuming regular game-week preparations Monday.
O'Brien wouldn't tip his hand as to a starter at two positions - running back and defensive end - where the competition is close.
In the overtime win over Michigan on Oct. 12, running back Zach Zwinak did not play another snap after his fumble on the first play of the second half led to a Wolverines touchdown. O'Brien said that he has practiced well and that Zwinak and Bill Belton both will play against Ohio State.
Deion Barnes, the former Northeast High star, did not start at defensive end for the first time this season, with Anthony Zettel getting the nod. O'Brien said he would rotate Barnes, Zettel, and a number of other defensive linemen because of Ohio State's swift read-option offense.
As for injuries, O'Brien said junior safety Ryan Keiser is "full go" after recovering from a hand injury. However, Keiser will not hold for kicker Sam Ficken as a precaution, and that job will go to either punter Alex Butterworth or freshman walk-on Adam Geiger.