In case you were wondering, O'Brien is the offensive coordinator as well as being head coach.
Through four games this season, the Nittany Lions (3-1) have averaged 74.3 plays compared with 76.5 for Indiana (2-2). The Hoosiers, however, are averaging 7.2 yards per play - a full yard more than the Lions - and are rolling up 44.5 points and 547 yards of total offense per game.
Indiana coach Kevin Wilson doesn't appear to have the same concern as O'Brien about wearing out his defense. The Hoosiers have struggled on that side of the ball, allowing averages of 463 yards and 33 points.
"We're trying to do what we can to score points to win," Wilson said. "We've also got to play better defense. So if [the fast tempo] hurts our defense, it does. But at the same time, I don't know if we play good enough defense that we can play conservative and score enough points."
Penn State is accustomed to practicing against a speedy tempo but O'Brien knows Indiana will present a different dimension with quarterback Nate Sudfeld and a strong corps of backs and receivers.
"That's a tough offense to defend," he said. "You have to make sure that you swing to the ball, that you tackle properly, that you get lined up and communicate and you're able to decipher the formation that they come out in and make sure you understand what they're doing."
Given the high-powered Indiana attack, O'Brien said he realizes that his team has to keep scoring with a mix of tempos, noting, "I don't think we can come out of this game with a bunch of field goals."
Like Indiana, Penn State is coming off a bye week. O'Brien said the time gave his staff a chance to look over tendencies as an offense and defense, and examine individual players to see where they can improve.
"Bye weeks are good," he said, "and obviously you've got to give guys that are banged up a chance to heal."
Nittany notes. O'Brien said starting linebacker Mike Hull is "full go" for Saturday after missing two games and a portion of a third with a knee injury. The coach said safety Ryan Keiser (hand) and special-teams player Jack Haffner (ankle) are out. . . . O'Brien said he has received "positive" reactions from recruits over the NCAA's decision last week to reinstate scholarships that had been cut by sanctions.