LAS VEGAS -- Floyd Mayweather may be the best fighter that no one will buy a ticket to see.

Mayweather moves up to challenge Jose Luis Castillo for the WBC lightweight title Saturday night -- and he's still unable to attract ticket buyers despite his unbeaten record.

Mayweather blames his promoter, Bob Arum, for not making him a bigger name. Arum says Mayweather is his own worst enemy, refusing to reach out to fight fans while getting in trouble outside the ring.

"We'll have a crowd of 5,000, which is ridiculous," Arum said. "And most of them will be Castillo fans."

One thing neither Arum nor Mayweather questions -- the ability of the 25-year-old fighter who made eight defenses of his 130-pound title before deciding to move up and bang with the lightweights.

"His talent is mind boggling," Arum said Thursday.

Mayweather is a 4-1 favorite to beat Castillo, a former chief sparring partner for Julio Cesar Chavez, and add the 135-pound title to his growing list of accomplishments.

He'll make $2.2 million to do it, though the money is coming from HBO and not ticket buyers at the MGM Grand hotel-casino. The casino this week gave back to Arum hundreds of tickets it reserved for high-rollers who aren't going to the fight.

Mayweather is still an enigma to most, though he claims he should by now be the kind of attraction that Oscar De La Hoya is in the ring.

"I was promised when I came here that by the time I was 24 I was going to be as big as life," Mayweather said. "They said they were going to promote me and do all of these things and none of them came true."

HBO signed Mayweather to the deal in hopes he would be able to headline as a pay-per-view attraction. He has yet to do so, however, because the cable network realized he would be a tough sell.

Mayweather has big plans to move up to 140 pounds and fight Kostya Tszyu and later challenge De La Hoya, but he may have the toughest fight of his career against Castillo, who is making the third defense of his title.

"I'm going to show the world what I'm made of," Castillo said. "I'm very confident and sure of myself I"m going to win it."

Mayweather is coming off a ninth-round stoppage of Jesus Chavez in November in San Francisco in which he did not look his best. Chavez came right after him and tried to fight inside, much like Castillo plans to.

But Mayweather says he's not taking the fight lightly despite the interruption of his training last month to get a six-month suspended sentence for two domestic assault cases involving the mothers of his children.

"I want to impress the fans," Mayweather said. "I'm looking to win impressively."

Even if Mayweather does win impressively he's not likely to get the pay-per-view fights he wants so badly. He's still basically unknown to most casual fans, partly because he doesn't try too hard to make a name for himself.

"He doesn't give the public an opportunity to identify and like him," Arum said. "He says so many bad things. He doesn't really think about what he's saying."

Arum and Mayweather have had a love-hate relationship since Arum signed the young talent fresh out of the 1996 Olympics. They've battled over contracts and opponents, but are still together through 27 fights.

But, just as Mayweather is upset over the way he's being handled, Arum is unhappy with the fighter. Mayweather can be petulant, refuses to talk to certain media people at times, and spends little time trying to groom an image.

Mayweather refuses to talk about the plea bargain on domestic assault charges. It may be partly out of embarrassment, since when he fought Diego Corrales in January 2000 he promised to give him a beating on behalf of battered women everywhere because Corrales had beaten his wife.

"The only thing I'm going to do is talk boxing," Mayweather said.