ANN ARBOR, Mich. -- Even though he's back, Sean Lee is still being careful with his sprained left knee.

He practiced three of the four days in the week before the Michigan game, and Penn State coach Joe Paterno is letting Lee and team doctors determine how much he practices and plays.

"At times he gets a little nervous, seems like it's getting sore," Paterno said. "We kind of let him call the shots. He doesn't need a lot of practice."

Defensive coordinator Tom Bradley said Lee probably could've remained in the game if the score was close. He played about 20 snaps Saturday, Bradley said, and hopes he can get back to seeing close to 60 plays a game.

Lee played in the nickel package and during passing situations at first, then got the OK to play one of the base defensive packages.

"Probably around the middle of second to the end of the third [quarter], I was playing full go," Lee said. "I felt fine. I felt normal."

Day to remember

Offense: QB Daryll Clark

The senior tied a career high with four touchdown passes and continues to avoid turnovers. Clark hasn't committed a turnover on the road this season.

Defense: LB Navorro Bowman

Bowman filled up the stat sheet with 11 tackles, a sack, an interception and a fumble recovery.

Day to forget

Offense : WR Chaz Powell

The wideout had a 54-yard kickoff return, which set up a score, and converted a third-and-two on an end around. But cycling through his reads, Clark never found Powell, who had four balls thrown his way. His versatility adds an element to the offense, and more touches wouldn't be such a bad thing.

Defense: DE Eric Latimore

Latimore was not in on any tackles and was left off Penn State's participation report. Defensive ends Jerome Hayes and Jack Crawford had big days and face another challenge keeping skittish Northwestern quarterback Mike Kafka in the pocket this Saturday.

Did you notice?

The clock stopping after a Michigan run play on its final drive of the first half ... All-time receptions leader Deon Butler on the sideline ... K-9 dogs sniffing bags at the media gate.

Extra point

Spread offenses seem to be the defense's forte, and that bodes well this Saturday at Northwestern, which runs its own version of the offense.

The Nittany Lions are good enough up front to pressure the quarterback and contain him when he leaves the pocket. The linebacking unit stays in its lanes to stuff the run and is athletic enough to cover the short passing attack.

Quotable

Paterno, on the game clock stopping in the second quarter:

"I don't know who the clock operator is, but if he was the same guy that was here in 2005 ... "