LOS ANGELES — Vivian Harris has suffered four losses during his 13-year career, including three by knockout, but the former 140-pound titleholder has never quit.

Harris (29-4-1, 19 knockouts) is always prepared to go out on his shield.

The 32-year-old veteran doesn’t believe Victor Ortiz, his opponent on the undercard of the Shane Mosley-Sergio Mora pay-per-view event Saturday in Los Angeles, is willing to do the same.

Harris isn’t alone in questioning Ortiz’s resolve. Many fans and some boxing writers have wondered whether the prospect of the year for 2008 has what it takes to be world-class professional ever since the 23-year-old southpaw turned his back on Marcos Maidana and stopped fighting after he was dropped by a body shot in the sixth round of their brutal shootout last June.

Harris is more blunt with his assessment of Ortiz (27-2-1, 21 KOs), who traded knockdowns with Maidana in the first round and twice dropped the Argentine slugger in the second before ultimately losing by a sixth-round TKO at Staples Center, the site of Saturday’s fight.

“He’s a quitter,” Harris told RingTV.com at a public workout held in downtown L.A. on Tuesday. “He fell apart in the Maidana fight and he’s going to fall apart on Sept. 18 because I come to fight and I hit much harder than Maidana. Things you’ve done before in the ring, you’ll do again.”

Many have branded Ortiz with the dreaded “Q” word but unlike fans and boxing insiders, Harris has no problem saying it directly to the young fighter. The Brooklyn-based native of Guyana said on a recent conference call with Ortiz that his foe lacks courage and hasn’t earned his No. 1 ranking in an alphabet organization.

If Harris sounds like a jaded veteran, it’s because he is. He took the hard road to a title shot, facing the kind of dangerous fighters better-connected contenders avoid, and he won a major belt in 2002. Although he defended it three times against top opposition over the next 2¾ years, his reign wasn’t as lucrative as he feels it should have been and none of his defenses were televised live in the U.S.

Harris is often his own worst enemy. Although an extremely hard worker in the gym, he can be stubborn when it comes to respecting his trainers’ wishes, even when that trainer is Hall of Famer Emanuel Steward. He’s combative with his promoters, he's notoriously difficult in negotiations and he has turned down some big fights in the past, including a showdown with a still-developing Ricky Hatton in 2004. However, Harris has received his share of legitimate raw deals.

A clear decision victory over Ivan Robinson in 2000 was officially ruled a draw because of an odd-ball majority scoring system that New Jersey’s athletic commission was experimenting with at the time. His last bout, a competitive fight with undefeated Argentine puncher Lucas Matthysse in Mexico City in February was abruptly stopped in the fourth round after Harris was caught — but not seriously hurt — by a hard three-punch combination.

“People wonder why I have been inactive at times in my career,” Harris said. “It’s simple: Promoters and the boxing biz have held me back. It’s hard to stay active and get the fights you want when you fight the biz and that’s what I do. I don’t give a f___. I speak my mind and I speak out when promoters treat me wrong. I fight the biz every day and I’ve been punished for it.”

Harris is an angry man but his me-against-the-world mentality keeps him motivated.

He remembers battling back from the brink of unconsciousness to narrowly outpoint hard-punching Jose Luis Juarez in a 10-round slugfest in 2001. He remembers fighting through rough moments against Souleymane M'baye and outboxing the then-undefeated (27-0) future beltholder to a unanimous decision in 2003.

Harris remembers the heart and character he showed in those bouts and then he reminds himself that those fights were stuck on the non-televised undercards of HBO double headers. When Harris thinks about the number of HBO dates Ortiz has received, the titleholder becomes extra motivated for Saturday’s showdown.

In many ways, Harris views Ortiz as his exact opposite — a pampered, protected creation of promotional hype.

“Victor is a good fighter but he’s not the star that Golden Boy made him out to be,” Harris said. “He’s nothing special. I saw that he doubted himself before the Maidana fight. After the Maidana fight, he’s become nothing but a front runner. He tries to get you out early and if he can’t do that, he tries to survive like he did against Nate Campbell.”

Oscar De La Hoya, who promotes both fighters, believe Harris’ verbal jabs at Ortiz will serve to motivate the young fighter as much as the veteran’s anger serves him.

“Those things Harris has been saying about Victor is going to fuel him,” De La Hoya told RingTV.com at Tuesday’s public workouts. “When Harris started saying those things during the conference call, I was thinking ‘Yes! Keep going. That’s what he needs.’ Victor has great potential but he needs to find that edge, and sometimes an older fighter who doesn’t respect you can give that to you.

“Every single veteran that I fought when I was coming up said those things to me. ‘He’s not a fighter, he’s just the media’s Golden Boy, he’s just hype.’ Those words made me train harder. I know what Vivian is trying to do. He knows that Victor could be affected by what he says, but I have a feeling it’s going to make him even stronger mentally.”

Harris says he hopes his latest promoter is correct.

“That’s great if it does,” Harris said. “It’s supposed to fire him up. I want him to come to fight, like I do. But if you don’t have it, you can’t get it, and no one can give it to you. If he had it, he would have shown it in the Maidana fight.”

David Rodela, one of Ortiz’s sparring partners for Saturday’s fight, says Ortiz used to have “it” and believes that his fellow Oxnard, Calif., resident has got it back.

“I think he’s got his swagger back,” said Rodela, a 130-pound prospect who has served as one of Manny Pacquiao’s most-reliable sparring partners over the years. “I tried to push him and piss him off. I wanted to pressure him to the point where he either sinks or swims and he swam. He swam so much he kicked my ass.

“We sparred soon after the Maidana fight and he wasn’t quite the same, but I think he’s got his confidence back.”

Harris isn’t buying it and he isn’t listening to what anybody has to say in support of Ortiz, at least not until they step into the ring.

“I don’t care what nobody says,” he said. “I don’t care what sparring partners, promoters, media, and critics have to say. Come Sept. 18, we’ll see who has what. That’s what this fight is about.”