Every 2-year-old with a toy football learns how. Matt Limegrover figures he can teach the finer points to middle-aged sportswriters in about five minutes. It's about as basic a move as there is in football.

So what's the big deal about snapping the football?

"Well, the act of snapping isn't too hard. I could teach anybody. I could teach you," Limegrover, the Gophers' offensive coordinator, said generously. "Now, when a defense puts a 310-pound guy who might be a third-round draft pick over the top of you, breathing fire down your neck, and you've got to snap it and then navigate what you're going to do with that guy, that's when the stakes are raised."

He makes a good point.

The stakes have been raised this week for the Gophers, whose numerous injury concerns mostly center on the center for Saturday's game at Nebraska. Starter Jon Christenson is nursing a sprained left ankle. Backup Zach Mottla is recovering from ankle surgery, so the Gophers' offense needs a new trigger man.

"In my 30 years, I've never snapped the third-string center in a game," coach Jerry Kill said last Saturday after left guard Zac Epping was conscripted into fill-in duty. "Usually you don't even have one on the road."

In Epping, they even had a little experience: The Kenosha, Wis., practiced at the position in fall camp and played early in the season.

"They told me at the beginning of the season, get ready to play guard, get ready to play center," the 20-year-old sophomore said.

The positions may be next to each other, but they're not identical, Epping said, and the contrasts go beyond hiking a football. "It's just completely different," he said. "You've got to be more mentally focused at center, and at guard, you've got to be more physical."

The intellectual part is important because centers, Limegrover said, are the quarterbacks of the offensive line. Each lineman has a little different perspective on how the defense is lined up, so it's up to the center to decide how to react and to communicate that read to his teammates. Snapping, in other words, isn't as critical as pointing and shouting.

"You have to make all the front calls. You walk up, look for the mike [middle] linebacker, and point out if it's an odd front, an even front, an Okie front, whatever," Epping said.

And the snap itself seems pretty straightforward, but like most things in football, it's been refined to its most technical DNA. "It's almost every play, you're reminding [the center], 'Hey, keep your wrist locked. Drive it back to your target. Don't get lazy with it,' " Limegrover said. "The mechanics have to be right."

Particularly in Minnesota's offense, where the quarterback stands several yards behind the line of scrimmage on almost every play, and someone is always moving before the snap. The Gophers have tried a "jet sweep" a few times, for instance, where the ball is snapped to a receiver at the instant he runs past the center. Plus, many of their passing plays, and even the zone-read runs, depend upon precise timing, which is easily disrupted if the quarterback has to take an extra second or two to track down an errant snap.

"So much of comes back to timing. If that quarterback is all over the place, that's hurting the mesh on the zone-read and the power-read," Limegrover said. "And if [the center] stops thinking about [the snap] and starts thinking about the guy across from him, that's when the ball ends up down at the quarterback's knees, or [the quarterback] looks like he's slam-dunking, trying to catch the ball. And that's when we get in trouble; because of our timing, the snap has got to be right in the heart of the numbers."

Quarterbacks notice all sorts of little details, and can tell who is snapping the ball without looking. Epping, for instance, is left-handed, "so it's a little different coming into your hand. The spin is different," said Gophers QB Philip Nelson. "Each center has tendencies, they snap it one way or another. That's way we practice with every one every day."

"It seems like a simple thing, but there's a lot to it," said Limegrover, who spent Tuesday preparing tackle Ed Olson as his emergency center. "I'm hoping [this week] we only need to play one."