"Look, he's a talented guy, he's got a long way to go. It's one game. He made some nice throws, he made some mistakes. I made some bad play calls and put him in bad situations. We'll just have to keep learning from each other. He's a fun guy to coach."
It's evident O'Brien has built a nice relationship with Hackenberg since recruiting him out of Fork Union (Va.) Military Academy. He was trusting enough to allow the kid - a freshman starting at quarterback in his first game on national television - to stand in front of about 50 inquiring reporters after the game, something that Joe Paterno never allowed.
Hackenberg handled himself well.
"It's a big change," he said. "I was definitely nervous. The guys really helped me through that. But once the game starts, at the end of the day, it's just football.
"It's been a big transition. I was playing [high school] baseball a little while ago. But I just tried to come in here and immerse myself, doing what I can to reach my potential."
Hackenberg was asked about the fact that he is leading a unit of much older players. Four members of his starting offensive line are 22 years old.
"It's a big adjustment," he said. "I'm only 18 years old and some of these guys are 20, 22. So just being able to talk with them is great. They look at me and I look at them with the same respect."
O'Brien disclosed that he had reached a decision on a starter between Hackenberg and sophomore Tyler Ferguson two weeks ago. He chided reporters for suggesting he was indecisive just because he hadn't revealed his choice publicly.
The coach said the battle was a close one.
Hackenberg "made his share of mistakes. They both did," he said. "I'd say it was pretty even. I wouldn't say one guy blew the other guy out of the water. I think it was fairly even. I had to make the decision for the team."
The decision might appear to be a good one. But as O'Brien says, there's plenty of time left in the season.
Contact Joe Juliano at email@example.com. Follow on Twitter @JoeJulesInq