The possibility of a Sugar Ray Leonard-Marvin Hagler middleweight championship fight has prompted opinions ranging from trainer Angelo Dundee's suggestion that such a match "would be part of history" to promoter Bob Arum's appraisal that it would be "ludicrous" for Leonard to attempt such a bout.

Two managers of professional boxers said that Leonard is capable of winning the title from Hagler should Hagler accept Leonard's challenge, but both said that Leonard would need tuneup fights before taking on the hard-hitting champion. One promoter, however, said it would be better for Leonard to go straight to Hagler.

Meanwhile, Hagler's manager, Pat Petronelli of Brockton, Mass., called Leonard's adviser, lawyer Michael Trainer, to exchange pleasantries but told Trainer he had not been able to reach Hagler, who was vacationing in the Caribbean. "I'd give my right arm to talk to him," Petronelli said from Brockton on Friday. "I've exhausted all my sources. I think he must be on a private boat." Neither Petronelli nor Hagler was available to comment yesterday.

Trainer said he believed from talking with Petronelli that Hagler had "heard about" Leonard's statements of Thursday that he wanted to fight Hagler and that Hagler "was on the way home. I don't know how he found out, skywriter or what."

What will happen next -- whether Hagler will go through with developing plans to fight Thomas Hearns in November, or fight Leonard first, later or at all -- "is up to Marvin," Trainer said.

"I've had the feeling that Ray has been looking at this guy professionally and he feels he can beat him," said Dundee, who would return to work with Leonard if Leonard got his wish to fight Hagler. "I did, too. We discussed it many, many times, prior to now.

"Then when I heard from my Washington friends that Ray was working out with Shawn O'Sullivan, I said, 'Uh-oh.' Ray's vibrant. He looks as good as ever. I don't think anything replaces being the guy in the ring. You know that attitude, lord of all you survey.

"This would not just be a fight; it's going to be a happening."

Lou Duva, manager for Mark Breland and other 1984 Olympic boxers, said Leonard knows what he is doing in wanting to take on Hagler.

"You don't beat Marvin Hagler on strength," said Duva. "You beat him on smarts. As far as smarts, I don't think anyone can beat Sugar Ray Leonard. Ray is banking on the style of Hagler to beat him. He's not going to beat Hagler 'the man,' he's going to beat Hagler 'the style.' "

Duva said Leonard's two-year layoff would not affect him. "Medically, you can throw that out the window," he said. "Ray has always been a superior athlete. I know every time I see him in different cities, he's out training on the road.

"The big thing I'm concerned about is really how much he wants it. I think if he wants it, he can overcome other hurdles. He's got a lot of soul-searching. He's got to look in the mirror and ask himself: 'What am I going to do if my eye bothers me in the fight?' I think Ray is smart enough that before making a statement like that, he must have had his eye checked out."

Leonard was operated on for a detached retina of the left eye in May 1982, and that November he announced his retirement. But in May 1984 he came back to fight Kevin Howard and was knocked down for the only time in his career before stopping Howard in the ninth round.

Duva said that before fighting Hagler, Leonard should test himself on another boxer. "That's the only thing I question," said Duva. "If he said he would take the two-fight deal, he could decide after the first fight whether he would go on. I can't see him going straight into that fight. But I think fighters in general fantasize."

Emanuel Steward, Hearns' manager, said Leonard owes it to the public and himself to be prepared if he were to fight Hagler. He said that Hearns and Hagler should fight, with Leonard taking on the winner. Steward presently is trying to set up the November bout with Hagler.

"Let me say this: He's been in some kind of shape, but there's a difference between workouts and actual competition," Steward said. "I think psychologically, Leonard will be quite paranoid. He won't have the head gear on to protect his eyes. With his eye, he will be a little hesitant. I think Ray is someone who is very concerned with his health.

"I don't think his reflexes will be off as much as his stamina. That's what he has been known for. I definitely think you need a couple of fights to find where you are. It's like football. You have a few scrimmages to find out if you're ready.

"I don't think it's fair to the public for them to come out for a one-time shot. I wouldn't say it's a complete mismatch, but he ought to get out and prove it to the public first. I think he would perform well to a certain degree. Ray is one of the great natural talents. I have tremendous confidence in Ray." 'He Wants to Do It'

One promoter, Dan Duva of Main Events, said Leonard-Hagler would "absolutely" be the highest-grossing fight ever. "There's no question," he said. "It would be the biggest fight of all time. I would think between the two fighters, they would get 20 million. The gross of the fight would be over 40 million."

Dan Duva said Leonard should bypass a tuneup. "I think he should go right for it," he said. "That's what he's mentally up for. The important thing is the fighting mentality. I don't think the weight is important. I think he'll beat Hagler. Most guys come back for the money. He wants to do it."

Lou Duva speculated that Hagler might be interested in fighting Leonard so he could conclude his career with the biggest fight in boxing history.

"I think with one big fight, Hagler and Leonard both may retire," he said. "Knowing Marvin Hagler, that with the problems he's having, he might fight Sugar Ray and call it a day. I think his wife has been after him to retire. They might want to fight in the greatest bout in the world. After the bout, there's nobody else. After that fight I would sit down and say, 'Let's have a cup of coffee and call it quits.' "

Steward, although he would like to see Leonard fight the winner of a Hearns-Hagler bout, still questions whether the retired welterweight should return to boxing. "I'm glad in some ways that he is coming back," he said. "I'm happy because it could bring lucrative situations. But I also don't want to see him come back. I don't see how much he can gain in history. The disadvantages outweigh the advantages. The Howard fight really kind of hampered his image."

Top Rank Inc. head Arum said Leonard should fight a "middleweight contender" before thinking of fighting Hagler, and that if Leonard fought Hagler directly out of retirement, "Hagler would take him out in 30 seconds. I'd look for a 30-second, one-minute fight."

Arum said it would be a "joke" for Leonard to come out of retirement solely to face Hagler. " Leonard had an undistinguished fight with Kevin Howard," he said. "His skills are sure to have eroded."

Arum, who was promoter of the Hagler-Hearns fight of April 1985 and stands to be the promoter of a Hagler-Hearns rematch if those arrangements go through, said he would be interested eventually in promoting a Leonard-Hagler bout but that for now he doesn't think Leonard is any match for Hagler.

"I don't want to turn the sport into wrestling," Arum said.

Trainer said that if or when Hagler said he wanted to fight Leonard, Trainer would sit down with Hagler's representatives and that the bout would be put together in the same fashion as the Leonard-Hearns fight of September 1981. "That fight," Trainer said, "was put together by the principals."

Trainer said it made no difference to him or Leonard if Hagler fought Hearns first. "Go back to what Ray said. He didn't put a time limit on it. He didn't say he had to fight him by Sept. 15 or the end of '86, just that he would fight him if he had the opportunity."

Trainer also said, "It's my understanding that there's no written commitment for Mr. Hagler to fight Mr. Hearns."

As if to emphatically punctuate his day-old challenge to Hagler, Leonard Friday cut, dazed and stopped a sparring partner in a workout in Palmer Park.

Looking fast and strong at 157 pounds, 10 over the welterweight limit at which he fought most of his fights, Leonard surprised his second sparring partner, Dominique Barry. Barry was moving forward, pressing Leonard, Leonard feinting and backpedaling, when suddenly Leonard came out of a crouch with a flurry of lefts and rights, stunning Barry with a left hook about three minutes into what would have been a five-minute round. Barry's cut eye was inspected, and the action stopped.

It was the first big blow struck by Leonard in his quest to fight Hagler.