The Associated Press

LAS VEGAS - Shane Mosley has much on his mind going into today's fight with Raul Marquez. He's coming off two straight losses, never has fought at 154 pounds and is in a money squabble over a planned fight with Oscar De La Hoya.

Mosley needs a good win to regain his confidence. At the same time, he knows a loss could threaten a career that once seemed without limit.

He also knows the worst thing he can do is bring all his thoughts into the ring against Marquez.

"I'm not thinking about De La Hoya or Bob Arum or anything," Mosley said. "I'm thinking about Raul Marquez, and that's all."

Mosley has plenty of reasons to keep his focus from wavering against Marquez, a former Olympian who for a brief time held a piece of the 154-pound title.

A loss - or even a bad showing - would kill Mosley's planned Sept. 13 rematch with De La Hoya, a fight that was supposed to pay Mosley $4.25 million and help him regain the stature that two losses to Vernon Forrest cost him.

Upset by Mosley's refusal to sign for that September bout, promoter Arum said he might withdraw the offer if Mosley isn't impressive against Marquez.

"If he struggles with this guy, who even needs him?" Arum said. "The fight with Oscar was contingent on him winning. Now it's more than just winning. Otherwise, forget about it."

The Mosley of old wouldn't figure to have too much trouble with Marquez in the scheduled 12-round fight (10 p.m. EST, HBO) at the Mandalay Bay hotel-casino. Marquez is both slow afoot and in his hands, and he was knocked out in two of his last eight bouts.

"I need a good performance for myself and for the fans," Mosley said. "I think it will be a great performance. This is my new beginning. I will be an exciting fighter."

There are questions about Mosley today, though, that weren't there when he beat De La Hoya in June 2000. After that, many were talking about Mosley as the world's best pound-for-pound fighter.

That was before Forrest beat him convincingly in their first fight in January 2002, then came back to win a closer fight in the July rematch. In neither fight did Mosley look much like the boxer who had won all 38 of his previous fights.

"I thought I won the second fight, and I believe Forrest thought the same thing, but that's in the past," Mosley said. "I didn't lose confidence in those fights. If anything, I gained confidence in the second fight."

Mosley's fast hands and punching power helped win him a title at 135 pounds, and he beat DeLa Hoya at 147. But he seemed small as a welterweight and is moving up to 154 pounds, where the punches tend to land a little harder.

"When you see me in the ring, you'll see it's natural," the 31-year-old Mosley said. "When you get a little older, the weight sticks on you more. My body still looks good, though. It's nice and hard."

Marquez (34-2, 23 knockouts) and Mosley (38-2, 35 KOs) spent time together in the gym while both were trying to make the 1992 Olympic team. Marquez actively pursued this fight with Mosley to try to get back into contention in the lucrative 154-pound mix.

"I've got no pressure," Marquez said. "I have nothing to lose. All the pressure is on him."

That pressure would ease greatly for Mosley should he look good Saturday, something Marquez vows will not happen.

"You don't have to worry about who is going to fight Oscar next," Marquez said. "I'm going to win."

Lara wins pro debut by defeating Sierra

AUBURN HILLS, Mich. - Octavio Lara, the 18-year-old fighter considered the best prospect to come out of Emanuel Steward's Kronk Gym in two decades, stopped Rafael Sierra in the third round to win his pro debut Friday night.

"All the pressure is off me now; no fight is going to be harder than my first one," Lara said. "He was pretty strong, but I was able to catch him with my two weapons - the Mexican left hook that I was born with and the Kronk right hand that I learned from Manny."

Lara showed defensive weaknesses, getting hit often by Sierra (5-3-1), but Lara dropped him with a straight right early in the third. Sierra got up but went down again after a left hook, and the fight was stopped at 2:09 after a combination put him on the canvas for the third time.

"A star is born," Steward said. "He was overmatched against a guy with eight fights, but he's got so much punching power that he got through it. You can feel the electricity when he's in the ring; this is going to be a great one. He's got that desire to win that Tommy Hearns had."

In addition to Hearns, Steward has trained champions Lennox Lewis and Julio Cesar Chavez at his Detroit-based gym, and Steward has said that Lara "could be as good as any of them."