In his mind, playing at Ohio State on Saturday night is not substantially different from that skirmish with Eastern Michigan back on Sept. 7.
"I have a thing about this. We talk about playing 12 one-game seasons, like every game is important," O'Brien said. "I understand, I totally understand the rivalry thing. But I think everybody is a rival, because everybody comes on the football field and wants to beat you and you want to beat them. So that's a rival."
Maybe that's so, but it's hard for 18-to-22-year-olds not to get amped up over playing the nation's No. 4 team from a neighboring state, with a shot at ending the longest winning streak (19 games) in major-college football.
The Buckeyes (7-0, 3-0 Big Ten) certainly look at the showdown as a rivalry, although Penn State (4-2, 1-1) remains a distant second to Michigan.
"I know they're a rival for us right now," Ohio State linebacker Ryan Shazier said. "I guess they're going to be our No. 2 rival. But right now I'm just looking forward to Saturday."
Here are five things to keep an eye on in the rivalry game that is not a rivalry game:
FRESHMAN TEST: A year ago, Christian Hackenberg was a senior playing QB at Fork Union Military Academy. Now he'll be stepping into one of the toughest environments in college football: Ohio Stadium.
Ohio State's Braxton Miller started as a freshman two years ago and knows what Hackenberg will be up against.
"It's hard," he said. "It ain't easy. It's hard."
Hackenberg has been terrific so far for the Nittany Lions—particularly when throwing to top target Allen Robinson.
"If we get into the pocket like we do against most teams, he might get a little nervous and force some throws," Ohio State DL Michael Bennett said.
TIGHT FIT: The Buckeyes have struggled to cover tight ends, particularly against Iowa's three-TE set last week.
When Penn State and Ohio State last met, the Buckeyes won 35-23 but graduated QB Matt McGloin's two TD passes were both to TEs. Kyle Carter, on the list for this year's Mackey Award as the nation's top TE, caught one of those, and he's back. Jesse James, who is 6-foot-7, and freshman Adam Breneman have also started for the Lions.
"They're very good players, they're big, they make matchup problems for us," Meyer said. "I know that they like to utilize them. If it's not concern No. 1, it's either 1a or 1b."
CRUNCH TIME: The temperatures are expected to just above freezing on Saturday night at the Horseshoe. Cold hands for quarterbacks and receivers may help the Buckeyes, who have a dependable running back in Carlos Hyde.
Hyde has averaged 159 yards rushing and has scored five touchdowns in his last two games. On the first cold night of the football season, he figures to loom large.
"He's obviously one of the better backs in the country," O'Brien said. "It's a huge challenge for us."
PASSIVE DEFENSE: Even though Ohio State has been methodically going through its schedule, it's not as if the defense has been particularly awe-inspiring.
In Big Ten play, the Buckeyes have given up 399, 437 and 375 yards of total offense, while surrendering 26 points a game. In the first half of last week's 34-24 comeback win over Iowa, the Hawkeyes relentlessly pushed around Ohio State defenders for the first half.
"We learned we have to be more of an attacking defense," said freshman DE Noah Spence, who originally committed to Penn State but now plays for the Buckeyes. "Not sitting and waiting for the play to come to us. Attack more. We're going to do that a lot more this week."
TOUGH SLATE: Things don't get a whole lot easier for the Nittany Lions after coming to Columbus. They play only one team with a losing record the rest of the way.
Their final five games: Illinois (3-3), at Minnesota (5-2), Purdue (1-6), Nebraska (5-1) and at Wisconsin (5-2).
One good thing: They can build on a dramatic four-overtime, 43-40 victory over Michigan in their previous game two weeks ago. They have some momentum.
Meanwhile, Ohio State plays at Purdue (1-6), has a bye week, hosts Indiana (3-4) then travels to play the Wolverines (6-1).
This week has Meyer worried enough.
"This is going to be a street fight for us," he said.
Follow Rusty Miller on Twitter: http://www.twitter.com/RustyMillerAP