THE RIVALRY: Saturday at the Coliseum, 12:30 p.m. : Their First Look : Poise, Ignorance Will Likely Work in McNown’s Favor

On a warm August night at the Rose Bowl, before a crowd of about 2,500, quarterback Cade McNown first took the field as a Bruin, running the team in an intrasquad scrimmage.

Although it was about as low-key a situation as a freshman could ask for, McNown, an 18-year-old only two months out of high school, admitted he was overwhelmed by the whole scene--the huge stadium, the crowd, the scoreboard.

Three months later, McNown, now UCLA’s starting quarterback, will take the field in another stadium for the first time Saturday.

If he was overwhelmed by the Rose Bowl in August, how will he feel about the Coliseum in November, trotting down that famed tunnel and out into the bright light along a path previously taken by football and track stars and Olympic legends, facing the roar of a crowd of more than 90,000, subjected for the first time to the fanaticism that is UCLA-USC football?

“I’ve never played in front of a crowd that big,” he said. “It’s just something I’ll have to deal with. I’m looking forward to it.”

If performance is any barometer, expect McNown to deal with it. Although his lack of experience in major-college football may cause him to be overwhelmed by his surroundings at times, it doesn’t seem to carry over once the ball is snapped. The impressive thing about McNown is the poise he exhibits once he leaves the huddle.

“He’s a lot more mature than me,” said Bruin center Mike Flanagan, a senior. “And he got that way real quick. He is so cool and calm out there, it’s almost scary.”

Although Saturday’s surroundings may seem overwhelming, McNown’s unfamiliarity with this rivalry may prove to be a factor in his favor, shielding him from some of the pressure.

Born in Oregon, McNown attended high school in both that state and Northern California. His only knowledge of UCLA-USC came via television.

Much of the ferocity of these games comes from growing up in Los Angeles, from having played with and against many of the players on the field back in high school, from knowing the agony and ecstasy that goes with the outcome of this game.

“It’s probably better for him that he doesn’t know what it’s all about,” said offensive tackle Jonathan Ogden.

But that’s not going to last. McNown is quickly learning about the significance of playing the Trojans, according to Flanagan.

“He has heard us all talk about SC, SC,” Flanagan said. “He knows about the shirts [with obscene references to USC]. When he walks out there and people are cursing at him, he’ll get the idea.”

The message, McNown said, is getting through.

“I’ve been told that whatever emotional highs I’ve experienced in the past, you can make that tenfold for this game,” he said.

Not for everybody. Receiver Kevin Jordan has been around for five years, counting his redshirt season, and he still doesn’t get it.

“It’s gotten bigger and bigger for me,” he said. “But, to be honest, I still don’t see why they make such a big deal out of it. Maybe that’s because I’m from Maryland. I guess it’s just for bragging rights, but I’m not into bragging.”

Learning to adjust to being in a game with USC is just the beginning of McNown’s task. He must then learn to adjust to the Trojan defense if UCLA is to have a chance.

With the status of Bruin tailback Karim Abdul-Jabbar uncertain because of a sprained right ankle, UCLA will go only as far as McNown’s left arm can take it.

And that arm has been unsteady of late.

When the Bruins were winning four in a row, McNown was a freshman sensation, connecting with his receivers consistently, running the option smoothly and even throwing a key block here and there.

But McNown has also been at the center of UCLA’s collapse in the last two games. Over six quarters, the Bruins have turned the ball over nine times. McNown has accounted for six of the nine, throwing three interceptions, missing his target twice on pitches with the result being fumbles, and also fumbling himself on one occasion.

But, at least outwardly, it doesn’t seem to have shaken his confidence.

“We just have to concentrate and focus,” he said. “When you play at a high intensity, like we will Saturday, the concentration will come.”

At least that’s what McNown expects to happen. But having never played in a UCLA-USC game, he doesn’t really know what to expect.