LAS VEGAS -- Since he lost to Lennox Lewis and Chris Byrd in a three-fight span over a period of about 10 months in 2000 and 2001, David Tua has been a different fighter.

The hardest puncher in boxing, Tua hasn't been shy about letting his opponent get a sense of his fearsome punching power. In fights against Garing Lane, Fres Oquendo, Michael Moorer and Russell Chasteen, Tua viciously threw his biggest shots even when it seemed he had no chance to connect.

It was the influence of his new trainer, Kevin Barry, who added that job to his duties as Tua's manager and chief confidante after Tua's loss to Byrd.

Barry insisted that Tua had to make his opponents know a big shot could be coming at any time from any angle. He got Tua to whaling away to such an extent that he sometimes seemed like a rank amateur.

It may not have appeared pretty to a purist, but it has been brutally effective. Lane was stopped in eight rounds, Oquendo in nine. Moorer lasted but 30 seconds while Chasteen made it into the second round.

But that's what a fighter can do with a trainer who knows him and who is in for the long haul, working with him tirelessly in the gym day after day, month after month and even year after year.

When Tua steps into the ring in the Philadelphia Spectrum on March 29, in the co-featured bout to middleweight champ Bernard Hopkins return to the ring, he'll know exactly what Barry expects from him. And Barry will know just which buttons to push to get the maximum out of his man.

But Hasim Rahman will have none of those advantages that night. He'll be accompanied to the ring by Miguel Diaz, who was in Las Vegas while Rahman was preparing for the Tua fight in Vero Beach, Fla.

Bouie Fisher will presumably be home watching on television, given that he was fired by one of the fighters in each of the fights.

And Buddy McGirt may be in the arena or he may be in Florida watching, but he definitely won't be in Rahman's corner.

Which raises the question: How important is a trainer on the night of a fight? Rahman is kind of a guinea pig, since he began camp with Fisher, fired him and hired McGirt but then won't have McGirt in his corner since a contractual dispute will keep the 2002 Trainer of the Year on the sidelines.

"Miguel Diaz will be the chief second that night and I'll be somewhere rooting for the Rock," McGirt says, coyly.

McGirt signed an exclusive contract with Main Events to work with its fighters. Don King promotes Rahman and relations between Main Events and King aren't particularly good these days. Main Events insisted it wouldn't let McGirt train Rahman.

So McGirt took over Rahman's trainer after Fisher's toppling, but won't be there to provide counsel in the corner on the night of the fight.

IBF heavyweight champion Chris Byrd says it won't make a bit of difference.

"At this level, it don't matter because you know what you have to do," Byrd said. "Why do you think Roy Jones hired Merk? He brought (trainer Alton Merkerson) in after his father left because he didn't want someone interfering and trying to tell him what to do.

"Roy knows what he needs to do. It's not like he needs anyone to look at tapes and make up a plan. He does that himself. Guys at this level have been around and they know themselves and they know what they have to do."

Rahman jokes about going from trainer to trainer to trainer and insists it's no big deal. And perhaps he has a point. The New York Yankees won plenty of World Series as George Steinbrenner was juggling managers like circus balls.

The fight is going to come down to one essential fact: The man who controls the distance is going to be the one who wins.

If Rahman keeps Tua at the end of his jab the way he did in their first fight on Dec. 18, 1998, it's going to be another long night for the Tuaman.

Barry was listening to a couple of visitors to a recent Tua workout session talk about what might happen in the fight when he said, "Dave is going to get up on his toes and box."

Right. And Barry Bonds will be voted Mr. Congeniality in the 2003 baseball season.

Tua can't afford to stay at the end of Rahman's jab and eat right hands. Rahman is bigger and stronger than he was on that night in Miami a little more than four years ago and even for a fighter with a chin as ironclad as Tua, that would be a bad strategy.

And Rahman can't afford to let Tua whack him with clean left hooks. Las Vegas sports books have set an over-under total of 10 full rounds and most bettors have wagered on the under, believing Rahman to have a glass chin.

Rahman laughs at the thought and says it is a misnomer.

"I didn't train at all for the (Oleg) Maskaev fight," Rahman said. "I was in no shape to fight then. The Corrie Sanders fight, people kept wanting to say I have a bad chin when I got knocked down. Ask (Wladimir) Klitschko about that now. Ask him if Corrie Sanders can punch.

"The guy can punch. Al Cole will tell you. Bobby Czyz will tell you. And the other time I got hurt was when I got hit by that shot from Lennox (Lewis) and there isn't anybody in the world who would have taken that shot. At least nobody human would have."

So maybe Rahman doesn't need a trainer. He knows Tua's punching power is devastating, though he says, "Watch the tape of the first fight. He hit me clean a number of times early in that fight and I just kept coming, beating his ass."

Focus has always been a problem for the immensely talented but largely under-achieving Rahman. He admits his training was non-existent for the Maskaev fight and incredibly said he wasn't focused when he defended the heavyweight title against Lewis in Las Vegas on Nov. 17, 2001.

"That first round, I hit Lennox with a left hook and I buckled his legs," Rahman said. "Had I been truly focused on what I was doing, I would have knocked him out again. But I wasn't really focused on the fight. I just kind of had this attitude that, 'Oh, sooner or later I'll hit him again and knock him out.' And that came back to get me."

Diaz is as sharp as they come and he'll be able to pick up any adjustments Tua is making and make the correct suggestions to Rahman. But the real story of the fight will come well before Rahman makes that long and lonely walk to the ring.

Can McGirt -- can anyone -- get to him and get him motivated and focused?

It's not like this is important or anything.

Only his boxing career is on the line.