A football field has been jammed into Wrigley Field's Friendly Confines so that Northwestern can host Illinois for an intrastate Big Ten clash Saturday in Chicago.

CHICAGO — The place is nicknamed the Friendly Confines, and, on Saturday, Wrigley Field definitely will live up to the “confines” part of it. A 120-yard football field (counting two end zones) fits into the 96-year-old ballpark with only inches to spare.

“Friendly?” Well, only if you’re not a wide receiver.

“I just told them they’re getting ready for the Arena League,” Illinois coach Ron Zook joked about the indoor league in which padded walls — like the one about a foot from the back of the east end zone, directly in front of Wrigley’s right field bleachers — are in play.

But nobody is complaining about the cramped dimensions or the small locker rooms or the single-sideline setup — both teams will stand on the north sideline, with a 10-yard buffer between the 45-yard lines separating them — at Saturday’s game between the Fighting Illini and the Northwestern Wildcats. The chance to play in such a jewel, the long-ago home of the Chicago Bears, is worth the trouble.

“If you can’t get excited about the things that are going on this week, you probably need to get yourself checked in,” Zook said at his weekly news conference.

That is exactly what Northwestern hoped for when the idea was proposed a couple of years ago. Wrigley Field hasn’t played host to a college football game since 1938.

But after being the site of several big rock concerts in recent years, and the NHL’s Winter Classic game on New Year’s Day 2009, a football game seemed like a natural fit.

But football isn’t the reason the game has been sold out for months. Fans are intrigued by all the quirky touches. The famous marquee outside has been painted Wildcats purple, since Northwestern is the home team. The east goal posts are attached directly to the right field wall, with no post underneath and no net, meaning extra points and some field goals will sail onto Sheffield Avenue like a home run.

Substitutions will be tricky when the teams are near an end zone, since one team’s subs will be half a field away. And that wall in right, where the bricks jut toward the playing field, could be a factor, too.

“I don’t think we’re going to be trying to run a lot of go routes” toward that heavily-padded — but still brick — wall, Northwestern coach Pat Fitzgerald told a Chicago radio station.

“It’s a recipe for disaster.”