Marco Antonio Barrera said that he never really left boxing, that he was just taking a rest. Most people thought the rest was permanent, though.

Barrera looked like a finished fighter when he was bloodied and beat up by Amir Khan 15 months ago yet is the latest oldtimer to return to the ring. The former six-time titleholder will face unknown Brazilian Adailton De Jesus on the Julio Cesar Chavez Jr.-John Duddy undercard Saturday in San Antonio on pay-per-view TV.

Barrera, only 36 but a veteran of 73 pro fights, says he wants to become the first Mexican to win titles in four weight classes.

“I never left the sport,” he said in his ever-improving English. “I am always here. Now I am here for maybe two, three or four fights. In Mexico City the TV is open and all the people will get to see me fight. I want to show all Mexico how I can still fight.”

But can he?

Barrera admitted that he has experienced at least some physical deterioration, saying, “My body, I feel change. I’m not the same (as) when I was 20.”

And he hasn’t had a meaningful victory since 2006, when he twice outpointed Rocky Juarez. Since then, he is 2-3, with victories over nobodies and losses to Juan Manuel Marquez, Manny Pacquiao and Khan. Six months after the Khan fight, he told RingTV.com that he was leaning toward retirement.

Now, he obviously believes he has enough left to make one more run at another title or at least make some money before he has no choice but to walk away for good.

Bob Arum, his new promoter, will move him quickly if he wins on Saturday.

“I hope to have him very shortly fight for a lightweight championship,” Arum said, “maybe against (Humberto) Soto or maybe against (Miguel) Acosta. Both fighters are under contract with Top Rank and so he’ll have that opportunity to ÔǪ be the first Mexican to win world titles in four weight divisions.”

Obviously, Arum signed Barrera (65-7, 43 knockouts) because he still has value. The future Hall of Famer has earned the reputation of being one of the most-exciting fighters of his era, with many classic wars against elite opponents.

That perception doesn’t change even when a fighter ages.

“Boxing is entertainment,” Arum said. “ÔǪ Some of these athletes don’t entertain. Marco Antonio Barrera has always entertained. He always comes to fight, whether he is a young guy fighting in the Los Angeles Forum or later on with classic fights against Erik Morales, he always entertained the fans.

“Fans don’t forget.”

We can only hope that fans won’t want to forget after watching Barrera fight again. No one wants to see a fighter of his stature end up on the wrong side of another bad beating.

Arum said he wants Barrera to go out in style.

“My goal is to do the rest of the fights in his brilliant career,” he said. “I want to bring him to the point where he wins four world championships and maybe a defense or two, and help him make some really good money.

“Then we’ll send him off to a proper retirement. That’s the goal.”