The immediate future is well defined in the mind of Muhammad Ali, in ways most of the men who held the premier title in boxing before him never even dreamed of.

The next 12 months or so should bear a comfortable similarity to the recent past. His life will continue to revolve around the ring, as it has for the better part of his 35-years. Beyond that time, he is uncertain.

Ali "retires" almost as regularly as Howard Cosell overstates a case, but he knows the time is not too distant when he will announce he's quitting and won't unretire the next day. Then his wide and ever-expanding world will have a new center of gravity.

He has pondered his future but reached no decisions as to which paths he'll follow. "Wherever God needs me," he said in a pensive moment last week. "It's such a big world, and everybody knows of me.There's so much I can do. But whatever it is will be boring compared to what I'm doin' now."

What he's doing this week is getting ready to defend his title against Alfredo Evangelita on May 16 in a tripleheader at the Capital Centre.

Ali is the Grand Marshal of what is billed as "The Parade of Champions." Alfredo Escalera will defend his World Boxing Council junior light-weight crown against Carlos Becerril on the same card, and lighweight champ Roberto Duran will fight a nontitle 10-rounder against Javier Muniz.

Evangelista, a 22-year-old Uruguayan-born Spaniard, is essentially an unknown quantity. That distinguishes him immediately from some of Ali's past opponents, who were tried and true stiffs - familiar and hopeless.

In the real world of boxing, unlike the large-than-life version that won an Academy Award for "Rocky" this year, there are few Rocky Balboas - fighters on the down side of mediocrity who get a title shot and rise above themselves.

There are, however, up-and-comers whose talent is not widely recognized until they meet an unsuspecting fighter of lofty reputaion. So it was with Jimmy Young, who lost a controversial decision to an out-of-shape Ali at Capital Centre on April 30, 1976, and has since decisioned George Foreman. Young was famous compared to Evangelista, who has never fought outside Spain in compiling a 13-1-0 (11 knockouts) record. But the point remains, until he confirms suspicions that his anonymity was richly deserved. Evangelista must be regarded with at least slight wariness.

Therefore, Ali is training seriously, if belatedly. Once again he has come to Our Town in less-than-peak condition. When he started public workouts Friday, his flesh jiggled like Farrah Fawcett-Majors', but not in the same places, nor as becomingly.

"I'll be gettin' up early, drinkin' some grapefruit juice, gettin' some of this fat off me," he said on arrival on Thursday. After hard physical work in the mornings, he allowed, he'd "go down to the gymnasium and knock out two or three guys."

Ali doesn't have time to get into the kind of shape he would need to face a Joe Frazier or Ken Norton but says, predictably, "I'll be ready. I don't underestimate anybody anymore." His target weight: 220.

Assuming he whups Evangelista, Ali says he would like to fight again in six weeks. "I'm gonna watch what I eat and keep training. I blow up easy now," he said. "I want to keep rolling - knock one guy out, bring another one in."

He is already pumping a rematch with Young, calling the Evangelista bout "a tune-up." Then, of course, there is the winner of Wednesday night's fight in New York between Ken Norton and Duane Bobick.

Norton broke Ali's jaw in winning the first of their three fights, all excruciatingly close, and many thought Norton had won a decision that went against him at Yankee Stadium last Sept. 28. Bobick, meanwhile, is the latest "Great White Hope."

"I have enough left to go one more year, two more tough fights. In those two, I expect to go about $14 million," Ali said. He is getting $2.75 million here, compared to Evangelista's $85,000.

Maybe I'll want four more fights," he added quickly. "I can do what I like. I'm the greatest attraction in the world."

Ali is not one to underestimate his own impact, and is acutely aware that the ring is his podium.

"When I grab the microphone after the fight, I'm going to thank Allah. I'm going to preach to the world," he said. "Even the President doesn't speak to the world, but I do. If I stop fightin', you know, well, 'Out of sight, out of mind.' But as long as I keep fightin', people write what I have to say.

"I'm in the newspaper more than anyone else of all time. The whole world is waiting for me to fight. All Egypt will be up early in the morning to watch me. In England, I'm the man. Same thing in Libya, Indonesia, Arabia, Morocco, the Philippines, Zaire, Pakistan, India, Hong Kong, Ethiopia, Afghanistan." He kept on rattling, countries and cities . . . a human gazeteer.

"When I'm on TV, nobody watches any other channel," he said. "Ain't nobody gonna watch 'Baretta.' Ain't nobody even gonna watch Nixon!"