If only the time and place were different -- if he were 10 or 20 years older, say, and similarly alone in a small, cluttered room at a resort hotel on the other side of North America -- maybe Thomas Hearns would have considered turning off the television, drawing a bright crack in the shades and asking the person knocking at his door to please enter or please go away.

Maybe he would have felt the early morning spent watching cartoons was an extravagant waste of time and ached with the feeling that infects most old champions of the fight game: the longing to recapture all the hours lost to brooding and introspection.

"What!?" Hearns said, making no move for the door. "You need something?"

But how many times can anyone fight Marvelous Marvin Hagler, even in conversation? You take the world middleweight champ through 15 rounds of headwork and you're left as tired and simple as old shoes.

This was, after all, Hearns' day off, a Wednesday almost one month before his April 15 challenge of Hagler at Caesars Palace in Las Vegas. And even though he wanted to be in the uninterrupted dark of his cell block on the 11th floor of the Eden Roc Hotel, the mayor hoped to present him with a proclamation, the city fire chief planned to make him an honorary member of the firehouse gang and a reporter demanded the obligatory 15 minutes.

Hearns, the World Boxing Council's super welterweight champion, answered the door with a stare that could have melted stones, one that left the numbing acid of remorse on the visitor's tongue. Earlier in the morning, Hearns' manager had lain in bed in his rumpled pajamas, wearing a collection of gold neck chains and bracelets, and attempted to describe the breadth of his fighter's intensity.

"Tommy Hearns comes into the ring like an animal breaking out of a cage," Emanuel Steward had said. "Someone once told me it's like a leopard unleashed and let loose to feed. You know he's about to explode, you can feel it. And then, all of a sudden, he's on top of you and you're going down. He owns this magneticism and this fierceness like no fighter I've ever known."

Now, Hearns was opening the door dressed in a black shirt unbuttoned to his navel and a pair of blue polyester slacks, long, nylon-ribbed socks and leather slippers he might have found on the shelves at the Salvation Army. His hair was fashioned in ringlets, with a single curl centering his forehead, and his eyes grew small and angry against the glare of hall lights.

"Last week at this time," he began without salutation, "I didn't stay in the room. I went deep-sea fishing, but the weather turned lousy and we never got out on the water. Then I went again the next Sunday, and I spent most of my time on the side of the boat, sick as a dog. I don't sail well. I had wanted to stay on the bay where it wasn't choppy and fish for bass. I like bass because they'll put up a good fight, but everybody else wanted to go out on the ocean. I ended up paying for it."

Every morning after Hearns' six or eight miles of roadwork, Steward makes breakfast for his fighter in the small kitchen that adjoins their suites. Hearns, whose only loss in 41 fights came against Sugar Ray Leonard on Sept. 16, 1981, says he rarely talks with Steward or anyone else about Hagler's weak and strong points. He chooses to address only his own skills, which are, as they say back home in Detroit, "pretty considerable."

"I don't even think about Marvin Hagler," Hearns said. "I don't care about what he can do and what he can't do, and I don't go out and prepare for it. My thing, I train myself for whatever may come. I'll figure out and take advantage of his weak points when I get into the ring. I'm a fighter. You take care of what you can and do your best to overcome the rest."

Hearns trains in the lobby of this luxury hotel set hard by the sugar white beach, in a ring planted over a dry fountain and surrounded by bronze statues of vestal virgins and muscular fellows attired in tutus. His toughest workouts rival those of Hagler, who has made camp at an equally exotic hotel in Palm Springs, Calif. Hearns has been using 18-ounce gloves during his workouts -- more than twice as heavy as the gloves he'll wear against Hagler -- and enduring four-minute rounds with sparring partners who have been instructed to fight as if vying for the middleweight title themselves.

By extending his fighter's six- and seven-round sparring sessions by one minute, Steward hopes to add to Hearns' strength and staying power. In challenging Hagler, Hearns, who stands 6 feet 1, or almost four inches taller than the champion, is stepping up in weight class, from 154 pounds to 160, but has a definite advantage in foot speed.

"You hear 'bout Tommy stepping up to fight a bigger man," Steward said, "but the biggest step up is for Marvin, and he knows it. Anytime Marvin has fought he's been a 5-to-1 favorite. But not one of those bouts has been against a great fighter. 'How bad will Marvelous beat up this little kid?' -- that's been Marvin's situation so far. But now, for the first time, he's going into the fight a betting underdog.

"Psychologically, Hagler will suffer hearing how strong Tommy is and how good his speed and right hand are. Everybody saw Hagler freeze against (Roberto) Duran, his only really big fight in a long time. They went 15 rounds and Duran pushed him around the ring.

"But when Tommy fought Duran, one good punch in the second round knocked him out. Tommy made it look easy. This is Marvin's biggest fight ever, but Tommy's already had four this big. And Marvin, who plays this tough-man game, has never been hit with the right hand. He's gonna get frustrated in Vegas. He's never had to deal with this kind of pressure."

Steward likes to show two contrasting Polaroid snapshots of Hagler and Hearns standing side by side before the photographers, posing with terrible gazes and fists held chest-high. The first picture, taken in 1982 -- the year this much-celebrated matchup was supposed to happen but which fell through -- shows "a little boy standing next to a man," as Steward put it.

"In the second picture, you have two men," he said. "Look at how much Tommy's matured in those three years. Both his facial expression and body definition have gone from boy to man. I've never seen anything like it. The transformation is so unusual, and I know it eats at Hagler. It's a whole new ballgame now. On top of that, Tommy's turned into a better boxer and he's a devastating one-punch fighter. And he's so tall.

"Hagler'll get frustrated trying to get inside . . . Even Leonard couldn't get inside. (Leonard) really got boxed silly against Tommy. His eyes closed up and he relegated himself to something like a club fighter trying to find one wild punch. Tommy was too quick on his feet for Leonard, and he was winning the fight. He just ran out of gas. The difference, though, is four years. Tommy's a man now . . . I don't see this fight going more than three rounds."

Hagler, now 30, still maintains that Hearns pulled out of the first fight because he was afraid and wanted to wait for "the bald-headed guy to become an old man." Hearns said that Hagler was "full of baloney." He added, "That's a big joke. When the first fight was made, there was money but nothing like what it is now. I'm proud the first one didn't go off."

Steward said the first fight was canceled because "the promoter came up and got a lawsuit against him and couldn't pay the money he'd promised." But Bob Arum, the promoter, laid the blame on Hearns, who was then an extremely angular 147-pound welterweight trying to regain momentum after the first and only loss of his professional career.

"Hearns was reluctant to do the fight, coming off the Leonard loss," Arum said. "He felt then that he hadn't matured enough physically or emotionally to take on Hagler, who was the older guy. So Hearns, at the first opportunity, really looked for an excuse not to fight. That led to a lot of bad blood between Emanuel Steward and myself. We felt like he finked out on us. The whole thing about Tommy's mother not wanting him to fight in Las Vegas -- Come on! This was back in 1982."

Hearns, who now is 26, has already held two world titles -- welterweight and super welterweight -- and hopes to win two more before retiring. After taking, he says, Hagler's middleweight crown, he said he wants to fight for the light heavyweight title, now held by Michael Spinks, sometime before his 30th birthday, "and 20 years since I first stepped in the ring," he said.

"This man that I'm facing is no greater than I am and I'm no greater than him. But I take a state of mind into every fight: 'I'm not gonna let this man do nothing to me.'

"I give no man no more respect than he deserves. If I think a man is good for only one round, I won't let him see the second. I will not carry anyone beyond what he deserves. I don't believe in that. Suppose you carry a fighter four or five rounds and you get head-butted and lose on a cut or you break a hand . . . With Hagler, I'm saying three rounds 'cause I feel like that's all I need."

Against Duran, Hearns predicted the fight would not last two complete rounds. The other day, when his visitor suggested he abandon the sweet science for work as a reader of tarot cards, Hearns replied quite seriously, "That Duran prediction came true but I really don't believe in calling the future. I couldn't read palms for a living. I'm a natural person who believes in natural things. But I think Manny believes in all that stuff. Who knows? I come strictly from the heart."