"The Replacements" is not just the title of a lousy 2000 football movie starring Gene Hackman and Keanu Reeves. It is the possible subplot for Saturday night's prime-time "whiteout" showdown in Beaver Stadium between undefeated, fifth-ranked Penn State and undefeated Iowa, the Big Ten opener for both schools.

Oh, sure, Penn State is known as "Linebacker U," but can coach Joe Paterno's team possibly be as effective on defense without either or both of its All-America candidates at the school's marquee position?

And what about Iowa, which always boasts a big, beefy offensive line and a thousand-yard battering ram of a tailback to run behind it? The Hawkeyes are making do with a patchwork o-line clearing the way for a couple of inexperienced, smallish running backs who weren't expected to play much, if at all, this season.

By the time another sellout crowd of 107,000-plus files out sometime after 11 p.m., it just might be that one team's perfect record (both are 3-0) will be preserved by a play made - or not - at a key moment by a backup or fill-in starter.

The unsettled availability of standout outside linebackers Sean Lee and Navorro Bowman is a major concern for Penn State coach Joe Paterno. If they can't go, their places in the lineup will be filled by redshirt junior Bani Gbadyu at strongside linebacker (in place of Lee, who has a sprained left knee suffered in last week's victory over Temple) and redshirt sophomore Nate Stupar at weakside linebacker (in place of Bowman, who has missed the last two games with a groin pull and whose return is a matter of conjecture).

Even senior middle linebacker Josh Hull, who will have to shoulder even more of a burden if he is not flanked by tackling machines Lee and Bowman, might not have retained his starting position had highly regarded Michael Mauti remained healthy. Mauti tore the anterior cruciate ligament in his right knee during the preseason and was redshirted.

"I'm worried," Paterno admitted when asked about the iffy status of Lee and Bowman. "Some of the kids who are starting to play a little more are getting better, but right now we can't count on any of the guys who were going to be the first three linebackers.

"We started out with the idea Mauti would give Hull a run for his money in the middle, and that Sean Lee and Bowman would be superior outside linebackers. If we don't have any of those three, that puts a lot on Hull. I'm not comfortable with the depth. I think Stupar is a kid that can be good, but he's a little erratic right now. And Gbadyu is pretty much like Stupar."

All of a sudden, those snide remarks about the Nits' soft nonconference schedule are being refuted by the injury report. What good does it to win a few meaningless battles if you end up losing the war? Bowman was pulled during the Sept. 5 season opener against Akron and was held out against both Syracuse and Temple; Lee limped off the field against the Owls and sat out most of the fourth quarter. Lee - gimpy or not, he was named Big Ten Defensive Player of the Week after he racked up 12 tackles and a sack - did not practice Monday, and Bowman worked only sparingly and at less than full speed.

Hull said no one should assume at this point that Lee and Bowman will be sidelined or hindered by game time.

"If they chain him to the bench," Hull responded when asked if he thought Lee, who missed all of the 2008 season while recovering from a torn ACL, would be held out against the Hawkeyes. Of Bowman, Hull was somewhat more optimistic, saying, "It's going to be exciting to see him out there again. He brings some leadership to the huddle. He's a real explosive kid that can make a big play at any time."

Paterno, more conservative when assessing Bowman's physical condition, said, "You don't want to stick him in there if he's not 100 percent. I'd hate to have him get another injury because he can't move as well as he should."

A year ago, Iowa's offense hinged largely on the power running of Shonn Greene, who rushed for 1,850 yards and scored 20 touchdowns. Greene is now a rookie with the New York Jets, but coach Kirk Ferentz thought he had a proven substitute for him in Jewel Hampton, who ran for 463 yards and seven TDs in 2008.

Hampton was lost prior to the season with a knee injury, though, which resulted in the forced promotions of redshirt freshman Adam Robinson and true freshman Brandon Wegher. Each has had their moments while splitting carries, but then neither has faced a defense as formidable as Penn State's, a task made more difficult if left tackle Bryan Bulaga, who is listed as day-to-day, is gimpy or sidelined.

Nit-picking

Wide receiver Graham Zug, who did not return to last week's game after complaining of a headache sustained during a punt return, apparently did not suffer a concussion and has received medical clearance to play . . . Joe Paterno certainly remembers last season's last-second, 24-23 loss at Iowa, but insists the Nits won't be playing for some payback. "I don't know what 'revenge' has to do with a football game," he said. "It isn't like they sneaked up on us and stuck us in the back with a knife." *