ROSE BOWL SHOWDOWN / UCLA vs. USC : Cook Is Cleared to Play Saturday : College football: Quarterback will wear extra protection for bruised kidney when he leads UCLA against USC at Coliseum.

During a period of midterms at UCLA, Wayne Cook has passed an examination that impacts his most important game of the season, perhaps of his life.

Cook, the Bruins’ quarterback, was declared sufficiently healed to start Saturday’s game against USC at the Coliseum. The winner goes to the Rose Bowl as the Pacific 10 Conference champion.

He had bruised a kidney in the first quarter of the Bruins’ Nov. 6 game at Washington State. Reserve quarterback Rob Walker struggled Saturday in UCLA’s 9-3 loss to Arizona, after which Cook said he would be ready to play against the Trojans.

First, though, he had to practice Monday and then take a urinalysis in the locker room to determine that the kidney was no longer bleeding.

“I was concerned, kind of, in the back of my mind (about the examination),” Cook said Tuesday. “I tried to be positive, but once in a while I’d catch myself saying, ‘What if?’ But I don’t have to worry about that now.”

Neither does Coach Terry Donahue.

“Any team is delighted to have their starting quarterback going into the biggest game of the year,” he said. “What’s really nice is to have it resolved early in the week so he can get a full week’s preparation as the starting quarterback, and we can get our team back in place and get things back to normal.”

Donahue had been told that Cook probably would be cleared, but, he said, “I didn’t get my hopes up.”

Cook threw passes Monday, getting used to wearing protectors for his ribs and kidneys. Tuesday, he threw easily and participated in every session.

“It felt good,” he said. “I didn’t feel like I was that off (after a week on the sidelines). For the most part, I threw well, and I’m glad I didn’t seem to lose anything.”

It remains to be seen how he functions Saturday against USC as the potential target of a blitzing linebacker. Cook has been sacked 16 times in nine games.

“I’m not going to worry about it,” he said. “If it happens, it happens. It might happen. People might think that by hitting me, they might take me out of the game, but I don’t see that happening.

“That’s the area (the midsection) they shoot for anyway. I mean if it gets hit, it gets hit.”

With that in mind, there might well be an extra incentive for the Bruin line to protect him.

“I don’t sense that,” said Donahue, “but I hope that that’s going to be exactly what the case will be. We need to protect Wayne Cook, and we need to do everything we can to make sure we keep him in the game.”

Cook has completed 120 of 219 passes for 1,601 yards and 16 touchdowns and has thrown only three interceptions in nine games.

The injury came early in the game at Pullman, Wash., when a Cougar, Singor Mobley, who was offside on the play, slammed into Cook. Cook returned to play, but again was hit and went back out.