LAS VEGAS -- Throughout his standout career, former three-division champion Shane Mosley has been known for his speed and power.
As lightweight champion, he made eight defenses and won each by knockout. He was also a two-time welterweight champion and unified belts at junior middleweight. Besides the power, Mosley's hand and foot speed were big reasons for his success.
But another one of Mosley's great attributes, even though it is rarely mentioned, is his stone chin.
Mosley has rarely been visibly hurt in a fight, despite facing numerous top opponents, and he has been knocked down only twice during his 18-year professional career.
The knockdowns came during the second round of his first fight against the late Vernon Forrest, who claimed the welterweight title from Mosley on that 2002 night at New York's Madison Square Garden Theater. Just before the first knockdown, Mosley had been severely hurt by an accidental head-butt.
Mosley (46-6-1, 39 KOs) is a significant underdog heading into his welterweight title challenge against pound-for-pound king Manny Pacquiao (52-3-2, 38 KOs) on Saturday night (Showtime PPV, 9 ET, $54.95) at the MGM Grand Garden Arena, so most expect a Pacquiao victory.
But a knockout victory would make it even sweeter, Freddie Roach, Pacquiao's trainer said.
"Shane's a tough guy, a very durable guy. It would be incredible for Manny to be the first one to stop him and just prove to the world how much better he is than that guy that couldn't stop him," Roach said, referring, of course, to Floyd Mayweather Jr., who outpointed Mosley with ease last May and has steadfastly refused to fight Pacquiao in boxing's biggest fight.
"I think Manny will fight at a fast pace. I don't know if [Mosley will] be prepared to fight at that pace, but we're going to force the action and we're going to go for it this time. If it comes, it comes. I think Manny is definitely the guy to do it."
Roach said if Pacquiao could stop Mosley, which Mayweather couldn't, it would be another feather in his cap -- as it was when Pacquiao stopped Oscar De La Hoya, which Mayweather couldn't do, and how he stopped Ricky Hatton in the second round, while Mayweather needed 10 rounds.
"That's why I'd try to knock him out, because I'd like to show how much better we are than that other guy," said Roach, who has taken to ribbing Pacquiao about how a knockout would help him negotiate a bigger purse in his next fight. "I think people measure things by that. They do."
Pacquiao, however, said he has other motivations.
"We're not focused for the knockout," he said. "All we do is work hard and if the knockout comes, it comes. We've prepared ourselves for fighting 12 rounds. What matters is the fight that we can give to the people and the fans. I want them to be happy and excited about our performance."
Said Roach: "I think all fights should end in knockouts, so I'm looking for a knockout."
Fight also available online
Top Rank is making the fight available online in the United States in addition to pay-per-view. Like the Showtime PPV telecast, the online version will feature the same lineup of fights and cost the same ($54.95).
However, the online version will also include interactive features unique to the digital platform through NeuLion's technology.
Top Rank president Todd duBoef said viewers will be able to select the audio track they want to listen to -- either Showtime's or Top Rank's announcers, or the international call of the fight. He said viewers will also be able to select which corner they would like to see between rounds and choose from a variety of camera shots and replays.
"This pay-per-view offering will complement our current distribution, which appeals to sports fans who are engaged in digital platforms on a daily basis," duBoef said. "Sports viewing has entered a new frontier and Pacquiao versus Mosley will be the pioneer for the boxing world."
The online version is available on www.toprank.tv, www.sports.SHO.com, www.cbs.com and www.sports.yahoo.com. Some cable and satellite TV systems will also offer the pay-per-view live stream.
The availability of the pay-per-view online is a byproduct of Top Rank's deal with Showtime/CBS to handle the event. When Top Rank was doing its major fights with HBO PPV, duBoef said HBO resisted its efforts to put PPVs online. When Top Rank took Pacquiao-Mosley to rival Showtime, with involvement from sister network CBS, Top Rank insisted it be able to offer a live Internet stream of the card.
Pacquiao fights for cause
When you see Pacquiao in the ring Saturday night, he will be wearing yellow gloves -- a color picked for a specific reason near and dear to Pacquiao's heart.
It will be in support of a charitable organization in the Philippines, Gawad Kalinga, that helps people in his home country out of poverty by helping them build homes. Pacquiao said the color yellow symbolizes unity and the fight against poverty.
If anyone knows about poverty, it is Pacquiao, who grew up with nothing, often slept in the streets in Manila and struggled for food. Now a multimillionaire, the Filipino congressman has made fighting poverty in his country the central cause he fights for in his political career.
"All my life, I've had to fight. As a child I had to fight to eat," Pacquiao said. "Now when I fight, the Filipinos call me a hero. I think the world needs more heroes.
"My biggest fight is not in boxing. My biggest fight is to end poverty in my country. I will be wearing yellow gloves into the ring on Saturday -- as a symbol of unity in the fight against poverty."
Top Rank promoter Bob Arum enjoys talking about Pacquiao's many outside-the-ring endeavors, including his humanitarian side.
"There's a joke that I made that, like the United States, the Philippines have a social welfare system," Arum said. "And they call it Manny Pacquiao, because he sponsors scholarships, beds in hospitals, food distribution. He is truly dedicated to help the poor people not only his country, but throughout the world. And, of course, he's a pretty damn good fighter."
Richardson stays with Mosley
Trainer Naazim Richardson works with Mosley and Bernard Hopkins, who have fights just two weeks apart.
But Mosley trained for Saturday's fight in Big Bear, Calif., while Hopkins is in training camp in his hometown of Philadelphia. Hopkins is preparing for his rematch against light heavyweight champion Jean Pascal on May 21 in Montreal. They battled to a controversial draw in December.
Richardson is good, but even he hasn't figured out how to be in two places at once, so he stayed with Mosley in Big Bear. However, he will be back with Hopkins on Monday for the final two weeks of preparation.
"Monday morning I will get off the plane and go right to the gym," Richardson said.
Richardson said he had Hopkins' blessing to be with Mosley.
"Bernard is a professional and there are not a whole lot of changes we have to make, because we already fought this guy and we know how to fight him," Richardson said. "Besides, the whole family is in place."
Richardson was talking about the team that always surrounds Hopkins at his training camp, including assistant trainer Danny Davis.
"I talk to Danny on the phone and we go over things," said Richardson, who said he made one trip from Big Bear to Philadelphia to check in on Hopkins.
Back in Las Vegas
Pacquiao is a beloved fighter among boxing fans, especially his Filipino countrymen. But casino operators in Las Vegas also love him because when he fights here he attracts high rollers galore.
Pacquiao's last two bouts -- against Antonio Margarito and Joshua Clottey last year -- took place at Cowboys Stadium in Arlington, Texas, for various reasons. But now he is back for his 12th fight in Las Vegas, and first since a 12th-round TKO of Miguel Cotto in November 2009.
MGM Grand officials are thrilled to have him back, and Pacquiao said he is happy to be back in the city where he has won numerous big fights.
"It's good to be back in Las Vegas. I miss being in Vegas for a big fight," Pacquiao said. "It's been a long time."
Arum, who lives in Las Vegas and whose company is based here, said he was also glad to bring Pacquiao back.
"It's no secret we've been out of Las Vegas with Manny Pacquiao fights for over a year," Arum said. "We had two fights in Dallas, but I'm happy to say we're back, because Las Vegas needs an event like this. Hundreds of millions of dollars will be brought into Las Vegas with this event.
"I live in Las Vegas and I thought it was time to come back to the place which is the capital of boxing. I think boxing needs Las Vegas and Las Vegas needs boxing."
The MGM Grand Garden Arena is sold out for the fight and will generate a live gate of about $9 million, not to mention millions more due to closed circuit ticket sales -- at $60 a pop -- that could reach 250,000, according to duBoef.
Pacquiao and Pryor?
Richardson has taken to comparing Pacquiao to Hall of Famer Aaron Pryor, a former junior welterweight champion known for his exciting fights.
"The reason I compare the two is that Aaron Pryor was an all-action fighter. He had a decent punch, but he was all-action," Richardson said. "You could just see his energy level was just extraordinary. And Pacquiao brings the same level of energy into the ring. And it's difficult to answer because he's so consistent.
"After he's fought bigger guys, his fights have gotten easier because the high-energy guys are at the lower weight classes. So when he's fought bigger guys, he's actually had an easier time."
This and that
The fourth and final episode of "Fight Camp 360°: Pacquiao vs. Mosley," the reality series that has followed the buildup to the fight, will debut at 10 p.m. ET/PT Friday and be replayed at a 2 p.m. ET/PT Saturday on CBS. ... Kenny Bayless will be the referee for Pacquiao-Mosley, with Duane Ford, Dave Moretti and Glen Trowbridge serving as judges. ... Pacquiao's official Nevada bout agreement calls for a purse of $6 million, although Top Rank has guaranteed him a minimum of $20 million because of expected pay-per-view sales. Mosley's Nevada contract calls for a purse of $3.95 million, but he is guaranteed at least $5 million. Both likely will make much more than their minimum guarantees because of the expected pay-per-view sales. ... Purses for the televised undercard fighters are Kelly Pavlik ($270,000), Alfonso Lopez ($40,000), Wilfredo Vazquez Jr. ($165,000), Jorge Arce ($125,000), Mike Alvarado ($50,000) and Ray Narh ($22,500). ... Pacquiao, whose first single in the United States was released last week, is scheduled to perform a concert at the Mandalay Beach following the fight.
Quotables
Pacquiao
"I'm motivated by my family and the boxing fans. I always motivated myself because this is my job and I have to train hard and work hard. I love to work hard. I'm always excited to train hard. I'm always motivated to train hard."
-- Pacquiao, on why he keeps working hard after all his success
"I see in the Margarito fight that Margarito landed the most punches ever on Manny Pacquiao. So if Margarito is fast enough to land punches on Manny Pacquiao, then I know I am fast enough to land punches on Manny Pacquiao."
-- Mosley, when asked how to compare his knockout win against Antonio Margarito to Pacquiao's easy decision against him
"I think I can do all the things I could do in the ring five years ago. Ten years ago -- I can't think back that far."
-- The 39-year-old Mosley joking when asked about his age and the fact that many believe he has slowed in recent fights
Mosley
"This fight is going to be a great fight. Me and Manny are both warriors. We both love to fight, we're both winners. When you get two winners in there, you know it's going to be a heckuva fight."
-- Mosley
"We're happy to be here and ready for a good fight. It's an honor and a privilege to witness one of the biggest upsets in the history of boxing, when Sugar Shane Mosley beats Manny Pacquiao."
-- James Prince, Mosley's manager, on his prediction for the fight
"If a bullet misses you by two inches, it's just as dangerous as a fly. It only matters if they land."
-- Richardson, Mosley's trainer, answering in classic Richardson-speak when asked about Pacquiao's combination of speed and power
Dan Rafael is the boxing writer for ESPN.com. Follow him on Twitter @danrafaelespn.