For three days this week, Digger Phelps, the Maestro of Marvelous Upsets, was stumped. He couldn't think of any possible way his Notre Dame basketball team could knock off No. 1 San Francisco Saturday.

Not even a quick trip to California for a couple of rounds of golf helped. So he finally gave up Tuesday night and took his wife to see the boxing film, "Rocky."

Now he thinks the Dons are going to be a knockout. "The more I watched the film, the more inspired I got," said Phelps. "I came home and stayed up to 1:30 putting together what I wanted to do.

"Everything fell into place, I put the team in Rocky's place. The underdog fighting in a big arena with fans yelling for him. And he puts up a valiant effort."

Phelps was reminded that Rocky also lost his bid for the heavyweight title. "My ending is different," he said with a laugh.

It's hard to argue with Phelps' track record. He feast on beating superior teams. In the last six years, his Irish squads have ended six different major enemy winning streaks, including UCLA's monstrous 88-game string in 1974.

"He's the king of the super psych," said senior forward Bill Paterno. "He has changed his approach since 1971. He doesn't yell as much but he's just as effective. Man, are we psyched for this game."

So are Notre Dame's frantic fans. They began yelling "beat San Francisco" at the Irish's last home game a week ago, and now things have reached an emotional peak on campus, concluding tonight with a rare basketball pep rally.

"This has become the greatest emotional game in Notre Dame basketball history," said Phelps. "Bigger than even UCLA. You can smell it on campus. The students want it, they can taste it. They won't quit."

Most of the nations basketball fans can taste this one, too. San Francisco, which will be making its first national television appearance this year in the 12:30 p.m. (EST) game, is an unknown quantity despite its 29-game winning streak and lofty ranking. The more the Dons have won, the more of a curiosity they have become.

That's why Phelphs seems to possess the Luck of the Irish. He scheduled this game last year on a hunch that San Francisco would have a "super season," then set the game for March "to give us both a good (NCAA) tournament warmup." Now his program, which is in the midst of a better-then-expected 19-6 year, will recieve national exposure it wouldn't normally expect.

San Francisco almost appears to have conceded that Phelps and his leprechauns will be too much to overcome. Coach Bob Gaillard stopped short today of saying the Dons will lost, but he spent much of his time talking about "how the real important games begin next week with the NCAA tournament."

"This is extremely important," he said, "but not critical. When we first became No. 1, I thought it was important for our program to stay there for a while. But after eight weeks, that doesn't matter anymore. In basketball, No. 1 is determined by the tournament."

So he says his team has things safely "in perspective." The Dons "want to learn by what happens out there," but they won't fall apart if we lost. We hope Digger will throw his whole bag of tricks at us. We want it as a learning experience to get us ready for the big games coming up."

On the surface, at least, Gaillard's soft-sell is working. Center Bill Cartwright, the man who eventually might make San Francisco fans forget about Bill Russell, called the game "a mild pressure experience. That's how we are approaching it."

But the Dons are disappointed enough in their last performance (a 95-92 victory over Portland) to ask Gaillard to call an unscheduled practice Monday. That doesn't sound like a team taking this game lightly.

"San Francisco has definitely got to be worried about playing here," said Paterno. "They have'nt been a national television and they've never seen a place quite like Notre Dame before. You come in here and you feel like the fans are going to destroy you.

"It's going to be a super experience far them. But it's something you don't adjust to immediately. It took UCLA four years to beat us here after my class arrived."

Unlike the UCLA-Notre Dame games, however, this is a lot more friendly rivalry. Phelps and Gaillard are buddies and they spent Thursday night hitting the high spots of South Bend.

"I wouldn't rate South Bend among my top three towns," said Gaillard, a relaxed sort who enjoys the night life of a city like San Francisco. "But it's better than buffalo. They've got gray hamburgers in Buffalo."

Whether Gaillard enjoys South Bend more Saturday afternoon probably will depend on what San Francisco team shows up. "We're either Dr. Jeckyll or Mr. Hyde," he said.

Dr. Jeckyll is a savage rebounding hot-shooting combination. Mr. Hyde is an outside gunning, mistake-prone misfit that stumbles to victories. Phelps and the Irish hope to draw out Mr. Hydes by throwing a combination of aggresive defenses at the Dons, which will prevent them from running.

"We can't get into a running game with them," said Phelps. "We want a final score of maybe 70-69. They want a score of 90-89.

"That's where the crowd will help us. Their yelling can inspire us, make us play better. It can help us keeping our poise, stay calm and not try to overwhelm them. This is a game where 90 per cent of it depends on our mental preparation."