By Ron Borges

The legendary trainer Cus D’Amato always insisted that a truly great but aging fighter who is not yet completely shot can muster from within himself one last night of glory. Marco Antonio Barrera needs to believe Cus D’Amato was right.

At 33, the great Mexican champion will square off with arguably the best super featherweight in the world, Manny Pacquiao, Saturday night at the Mandalay Bay Events Center in Las Vegas in what he has said for weeks now will be his last fight. After struggling to beat Rocky Juarez and then being unable to muster enough fire to hold off Juan Manuel Marquez in his last outing, Barrera has all the look about him of a spent shell. Most boxing experts feel he is well past the point D’Amato spoke of, his greatness now rusted over by the wear and tear of 69 prize fights and 18 years of nights spent in professional boxing arenas.

There is a price even the greatest fighters pay for their labors and while Barrera is among the very finest fighters Mexico has ever produced he is also someone who has paid mightily for his warrior’s approach. Never was that more evident than when he first faced Pacquiao nearly four years ago.

That night Barrera was considered to be among the very best boxers in the world while Pacquiao was a young lion pacing in his cage, looking for something to devour. He was not yet a national hero in the Philippines nor a household name except among true boxing aficionados but that night he became both by destroying Barrera in 11 grueling and one-sided rounds.

Although Barrera went on after that to defeat Erik Morales, another Mexican legend, in a rubber match of their great trilogy and twice held off Juarez to retain the WBC 130-pound title, he never again seemed quite the same fierce warrior he’d been before Pacquiao dismembered him.

Now he will face him again with the roles far different than they were that night. Pacquiao is now considered the most dangerous fighter in the world at 130 pounds while Barrera is the pacing lion. But he is not a young one like Pacquiao was on Nov. 15, 2003. He is an old lion with a graying mane, a lion still capable of roaring angrily into the night but perhaps no longer as able to run down his prey.

When an athlete begins to talk of retirement many believe he is already retired. In a sport as ill-tempered and unforgiving as prize fighting that is truer than in basketball or baseball, where perhaps one can muster one last moment. Fighting is different because the demands are high and the cost even higher. To have already decided you want no more makes it all the more difficult, when the harsh moments come as they surely will, to push yourself through the fire.

If Barrera does not quite yet realize this he need only look at what happened to his long-time rival, Morales, in his last fight with Pacquiao when he went down several times and needed less than three rounds to decide to sit on the floor, his knees tucked under his chin and watch himself counted out.

Another of boxing’s greatest warriors met the same fate when Arturo Gatti was beaten into submission in back-to-back fights by first Carlos Baldomir and then former “Contender’’ series loser Alfonso Gomez. Both times his spirit was broken more than his body was, although he took terrible punishment in each fight.

Neither of those men was able to muster up any more the moment D’Amato believes some great fighters still have buried within them. Might it be different for Barrera? He thinks so but when one listens to him speak of the night to come one wonders.

“Retirement is a decision I made,’’ Barrera said. “I basically am planning to retire. It’s not a decision I made overnight. Within the last three years I’ve been thinking about it. I’ve talked it over with my wife, my family and my friends and it’s something I really want to do.

“I just feel that I’ve been in this sport for so many years. Twenty-six years I’ve been in this sport. Eighteen as a (professional) fighter. I’m really ready to pass the torch. All those guys that are calling out my name that want to fight me, let (Edwin) Valero fight them. This should be my last fight.’’

If it is indeed his last fight, Barrera is conceding he knows what he is not. He is no longer the Barrera who once ruled. The Barrera who once dominated. The Barrera who once lived for moments like the one to come against Pacquiao. Without that can he still push himself off his stool when his body aches and his mind has been numbed by too many punches?

Not even Barrera knows that but he seemed to unknowingly speak of a bigger problem when asked what he would do differently this time against a man who dominated him when they first met.

“You know, there’s not too much I can change,’’ Barrera (63-5, 42 KO) said. “I’m 33 years old. I’ve been boxing a long time. I have my style. People know the way I fight. Everybody knows me, you know? I really can’t go into details but I’m just going to make it a good fight.

“The first fight you can basically throw it out the window. It was a bad night. The big difference between the first fight and this fight is the preparation. The preparation I had for this fight is so good. I just feel so confident.’’

Admittedly, Barrera’s training situation before the first fight was a nightmare. Controversy swirled around him both because of managerial problems and reports he had undergone a brain operation in Mexico to insert a small metal plate in his head over a burst blood vessel.

Those problems were compounded when a forest fire forced him out of his mountain training retreat, a disruption from which he says his camp never fully recovered.

Yet while those things are behind him, his problems with the 28-year-old power punching Pacquiao (44-3-2, 35 KO) are not. Asked what the difference was between his opponent today compared with four years ago, Barrera conceded he was a better fighter and a more experienced one. If he’s better and the soon-to- be retired Barrera is worse, how can the outcome reverse itself?

Thanks for asking.

“The first fight was a total meltdown,’’ Barrera said. “I can’t really take anything from that fight. It was Manny’s night and he took it to me but this fight the inspiration is within me. It’s personal.’’

Barrera claims Pacquiao’s record of consistently beating up Mexican opponents is on his mind as well as is his own sad experience with him and he intends to avenge all those lickings. Marco Antonio Barrera is saying all the right things. His words sound firm and his resolve complete.

But that is all they are. Words. When the bullets start flying what good then are words and empty promises from a man already convinced to buy a new Barcalounger chair?

“I know this guy,’’ Barrera says of Pacquiao. “I see him in my sleep. I see him all the time. I know exactly what he does. I know how he fights. So I am prepared.

“The motivation of the nay-sayers, the people that are putting me down, I like to shut their mouths. It’s happened in the past, you know, that they criticized me. They told me I was done but I came back and shut their mouths. Just because you watch boxing doesn’t mean you’re an expert. I like to prove them wrong and this fight, more than anything, I’m going to have a chance to do the same thing. It’s something personal I have inside.’’

That may very well be what he believes but what a fighter says before a fight is often not related to how he performs because boxing is the art of illusion and self-delusion. Usually the more difficult the former becomes the more often the latter comes into play and so it seems with Barrera, who in the very next moment after talking about how he sees Pacquiao in his sleep reaffirms the point that seems most important to him now.

“My mind is set,’’ the three-time world champion said. “This is the last big fight I’m doing. If I do lace them up again it’s for a retirement fight and it’s not going to be against a top-level guy. I’ve had so many tough fights in my career I’ve decided this is the last big fight I’m having.

“I don’t want to do anymore big fights. They’re not in my head.’’

If that is what’s in his head, how much room is there for thoughts of Manny Pacquiao? More importantly, how much room will there be for thoughts of pressing on through blood, and pain and exhaustion on Saturday night if the Filipino southpaw again starts to punch holes in his defenses as he did so readily four years ago?

What keeps Manny Pacquiao in his mind, and thoughts of the barcalounger chair out of it once the two of them are standing at hell’s doorstep?

No one knows. Perhaps, as Cus D’Amato has said, Marco Antonio Barrera can do it one last time because once he was a great, great fighter. Just don’t bet on it.