Wallace, a junior, made his first start of the season in last week's 20-6 victory at Purdue, but even though he is healthier now than he has been all season, he might not get another chance at the expanded role coach Joe Paterno had in mind for him. That's because some of the additional duties he was supposed to take on now have gone to a pair of redshirt freshmen, free safety Drew Astorino and safety-turned-wide receiver Chaz Powell, who have shown flashes of brilliance.

It wouldn't be much of a shock to anyone who has been paying close attention to the Lions' climb up the national rankings if Astorino and Powell continue to make their presence felt Saturday when No. 6 Penn State (6-0, 2-0 in the Big Ten) visits Wisconsin (3-2, 0-2) for a prime-time game (8 p.m., ESPN) in Camp Randall Stadium.

Astorino, a 5-10, 190-pounder from Edinboro, logs lots of action as the nickelback and primary backup to senior free captain Anthony Scirrotto, while Powell, a 6-1, 194-pounder from New Freedom, has been a big-play threat since the very first time he touched the football in a real game.

Makes you wonder what might have happened had Wallace, a junior, not tweaked that hamstring.

"We thought we had three corners coming into the season that had experience and could play," Paterno said, referring to Wallace, Lydell Sargeant and Tony Davis, who was moving back to cornerback after playing the 2007 season at free safety. "Then A.J. got hurt.

"We believed A.J. would play a little bit of offense as well as defense. We had it in mind that he'd be kind of a backup guy to [senior all-purpose threat] Derrick Williams, in case Derrick got banged up or tired."

Williams, of course, is Penn State's dynamic jack-of-all-trades. He catches passes, returns punts and kickoffs, occasionally carries the football on end-arounds and even on direct snaps. But Wallace has Williams' sort of breakaway speed, which made him a viable option for the same sort of multitasking. Wallace had, in fact, been used in various capacities as a true freshman, occasionally lining up as a wide receiver (he had one catch for 5 yards in 2006), carrying the ball eight times for 153 yards (an average of 19.1 yards per try) and one touchdown and returning 16 kickoffs for 388 yards (an average of 24.3).

But it's difficult to perform only one role, much less four, with a balky hamstring, an injury that opened the door for Astorino and Powell to make it onto the field more often.

Powell had fans in Beaver Stadium thumbing through their programs in the Aug. 30 opener against Coastal Carolina, a 66-10 romp, when he sprinted 55 yards, untouched, on an end-around for a third-quarter touchdown that boosted Penn State's lead to 59-7.

At the midway point of the season, Astorino leads the team with two interceptions - seven other players have one apiece - while Powell has six carries for 68 yards and another rushing touchdown to go with two receptions for 37 yards.

"Nowadays you have to be ready for a lot of spread," Paterno said of the wide-open offenses his defense frequently faces. "You need that extra defensive back. We're fortunate that Astorino has come through the way he has."

And Powell?

"I would think we would see more of Chaz as the season goes on," JoePa added. "We moved him to backup wideout, doing some of the things Derrick Williams does, things that we thought we'd do with A.J. before A.J. got hurt.

"Chaz should be playing more and more. Potentially, he's a very good football player."

Nit-picking

Jordan Norwood, who has missed the last two games with a sore hamstring, was judged to be "about 80 percent" back to full speed by quarterback Daryll Clark. JoePa, meanwhile, said he expects Norwood to be in the lineup as the slot receiver on Saturday night . . .

Of Wisconsin's beefy offensive line and power running game, defensive end Josh Gaines said, "It's a man's game when you play Wisconsin. They're going to put those big bodies on you and test your manhood." *