The promoters of the Floyd Mayweather Jr.-Juan Manuel Marquez pay-per-view card on Sept. 19 in Las Vegas are fighting for the fans’ dollars in a struggling economy. So they’re not taking chances.

They’re touting the undercard as the best since the days of multiple major title fights on Don King’s shows in 1990s. Only you can decide whether that’s true, but the fighters beneath the main-eventers have credentials.

Rocky Juarez vs. Chris John. Michael Katsidis vs. Vicente Escobedo. Zab Judah vs. Antonio Diaz. These are all established contenders who bring interesting styles and story lines to the card.

Richard Schaefer of Golden Boy Promotions, co-promoter with Mayweather, is probably accurate when he says that the Juarez-John and Katsidis-Escobedo fights could stand alone as main events on HBO.

“It takes a lot of money to put these kind of events on,” Schaefer said on a conference call, which included several of the fighters. “(Mayweather) said he wanted to give the fight fans their money’s worth. He delivered and the matchmakers executed.

“I think sports fans will embrace this kind of event. ÔǪ Hopefully it’s the first of many pay-per-view cards like this.”

Here’s a look at the three main undercard fights:

Juarez-John: The fight, for John’s featherweight title, is a rematch of a draw in February in Juarez’s hometown of Houston. It’s also Juarez’s fifth opportunity to fight for a major title, having fallen short in the first four.

Juarez (28-4-1, 20 knockouts) can thank his promoter (Golden Boy) and manager (Shelly Finkel) for all the title shots. However, this probably would be his last one if he loses.

And if he never does win a title?

“I don’t like to look at it like that,” the former U.S. Olympian said. “I’ve been a fighter who has been blessed, being able to compete at the top level of competition. I’ve never ducked any fighter. I’ve always gone up against the best fighters. Although I’ve come up short, I’ve never given up, never stopped. I’ve always given 110 percent. I’ve always been happy with myself.”

However …

“My goal was always to become a world champion. ÔǪ I know this is probably my last opportunity. I’ll be very prepared come Sept. 19.”

John (42-0-2, 22 KOs) might be the best boxer ever from his native Indonesia and he wants to prove how good he is in the U.S. He believes he was the victim of a hometown decision in the first meeting with Juarez.

He doesn’t plan to take any chances this time.

“This time, in the rematch, I want to fight very aggressively,” he said.

Katsidis-Escobedo: The 12-round lightweight bout is bound to be entertaining because Katsidis (25-2, 21 KOs) is a wild man. Oscar De La Hoya said the Australian “defines what a true warrior is.”

Katsidis is still rebuilding after consecutive losses to Joel Casamayor and Juan Diaz in 2008, after which he’s won two straight. He’s coming off a knockout victory over Jesus Chavez in April in Austin, Texas.

“I’ve come back from two losses. Many fighters don’t come back from that,” he said.

Escobedo (21-1, 13 KOs) also is trying to get to top. The 2004 U.S. Olympian has yet to live up to expectations, even his own.

His only loss, to Daniel Jimenez in 2006, set him back emotionally but he has established momentum since joining forces with trainer Nacho Beristain in 2007. He has won 12 in a row since the loss.

“After the loss to Jimenez, my confidence kind of went down,” he said. “ÔǪ Once I (switched to) Nacho Beristain, things started changing. He’s more my style. I started learning much, much more. It came down to trainer and confidence.

“Little by little I’m coming back, getting better and better.”

And Escobedo knows what it is to go to war. On the same card that Katsidis stopped Chavez, Escobedo outslugged veteran Carlos Hernandez in a spirited brawl.

Judah-Diaz: This 10-round fight – at a catch weight of 144 pounds – pits two grizzled veterans against one another.

Judah (37-6, 25 KOs) is a former multiple belt holder who has been in the title picture for more than a decade. The 31-year-old from Brooklyn, N.Y., is 3-4 in his last seven fights (with one no-contest) but never seems to go away.

Diaz (46-5-1, 29 KOs) did go away, taking a three-year hiatus from the sport. During that time, he got fat – blowing up to 205 pounds – but also allowed his body to recover from many ring wars.

He was inspired to come back by watching his brother, Julio Diaz, train.

“I saw him work out,” Diaz said. “I started doing a little work out, a little road work, a little sparring, and my body started feeling better than before I stopped. That motivated me to get back in the ring.

“I put on a lot of weight during the layoff. I was up to 205 pounds. I started going down gradually and felt good, healthy. My reflexes were still there. ÔǪ My body felt good.”

Diaz is 4-0 in his comeback, including an impressive victory over prospect Javier Castro in his last fight in March. He’s confident going into the Judah fight.

“I think he’s a little too small,” Diaz said. “I’m the bigger man. I think I can go in there and wear him down. That’s exactly what (Miguel) Cotto did. I plan to do the same thing, break him down ÔǪ and go from there.”

Michael Rosenthal can be reached at [email protected]