Manny Pacquiao hardly needs added motivation to work hard ahead of his May 2 mega-fight against Floyd Mayweather, but a personalised gift from celebrity lawyer Robert Shapiro has provided some nevertheless. The Pacman laughed with trainer Freddie Roach on Monday after Shapiro, most famed for representing OJ Simpson in 1995, gave him a custom-made speed ball with Mayweather's face painted on it. Pacquiao's speed and work rate are expected to be his biggest weapon against Mayweather when they take the ring in less than three weeks at the MGM Grand Garden Area in Las Vegas. Manny Pacquiao inspects a speed ball with the face of Floyd Mayweather painted on it during a break from training on Tuesday . Pacquiao and his trainer Freddie Roach (right) laugh at the gift given by celebrity lawyer Robert Shapiro (centre in the white hat) Robert Leslie Shapiro, 72, is a civil litigator working out of Los Angeles-based firm Glaser Weil Fink Jacobs Howard Avchen & Shapiro. Most famously, Shapiro was an integral member of OJ Simpson's 1995 defense team when the former NFL player successfully fought charges that he murdered his ex-wife Nicole Brown and Ronald Goldman in 1994. Other star clients include baseballers Darryl Strawberry, José Canseco and Vince Coleman, along with Johnny Carson, the Kardashians, Ol' Dirty Bastard and Linda Lovelace. In the US, he also appears in TV commercials for LegalZoom, a company he co-founded. Pacquiao is the underdog for the bout, billed as The Biggest Fight In History and tipped to gross more than £300m, but you wouldn't know it from his quiet  confidence as he works through the closing stages of preparations with Roach at his Los Angeles base. While sparring has been strictly off limits to all but their inner sanctum, Pacman looked fresh and sharp as he limbered up and shadow boxed during his session on Tuesday at the Wild Card Boxing gym, just off Santa Monica Boulevarde in Hollywood. For victory the eight-division world champion must do what no-one has done in Mayweather's 47-fight career and inflict defeat on the Money Man from Michigan, a five-division world champion in his own right and, of course, the holder of the welterweight titles they'll be fighting for. Pacquiao works up a sweat as he shadow boxes during preparations for his May 2 clash with Mayweather . With his eyes closed and grimacing with effort, Pacquiao ramps up his shadow boxing routine on Monday . On his toes and focused, Pacquiao is looking to defy the odds against fight favourite Floyd Mayweather . Roach kneels in the corner as Pacquiao's team prepare the eight-division champion for a session on the pads . The Filipino works his way around the ring, looking sharp after sharing a joke with Shapiro and Roach . Pacman limbers up ahead of his workout on Monday in the gym just off Santa Monica Boulevarde in Hollywood . Pacquiao is going through his final preparations ahead of the bout billed as 'The Biggest Fight in History' Confident Pacquiao kicks his feet high during his warm-up ahead of training at Wild Card Boxing . There have been no shortage of reports out of both camps that the other's preparations are below par. Pacquiao's promoter Bob Arum claimed Maywether's sparring has been limited by a split lip, which was later confirmed in an eye witness report from David Mayo from MLive.com, in addition to some cuts on his knuckles. 'Let me confirm that Mayweather indeed has been coping with hand injuries. He has some skin marks on his knuckles. They require antiseptic. He even sometimes blows on them to relieve the stinging after the medication is applied, lest anyone think it is impossible to hurt boxing's pound-for-pound king,' Mayo wrote. They aren't injuries to be worried about though, says Mayo, just like the reported calf problems Pacquiao is said to have been struggling with. 'Mayweather is 38. Pacquiao is 36. It would be a surprise if they didn't have some aches and pains. And it would be an excuse if anyone said a split lip or cramping calves in early April had any effect on a fight scheduled in early May,' he added. It's thirsty work for Pacquiao with less than three weeks to wait before he takes the ring against Mayweather . Pacman takes a rest against the ropes during his tough workout with Roach and his close-knit entourage . Last week Pacquiao's own sparring was cut short after US Anti Doping Agency technicians arrived to take four vials of blood for routine testing ahead of the fight. Roach decided to call it a day for his fighter, who had only been running the day before. Boxing Scene reported Arum saying that Pacquiao didn't want to keep the USADA officials waiting so gae blood and urine before his workout. 'Since it took a while to get it done, Freddie (Roach) asked Manny to take off,' Arum reportedly said. Arum then said Mayweather was 'getting hit a lot by his sparring partners and couldn't spar for a few days because his lip was cut and they had to manufacture a special headgear that also covered his lips because every time Floyd got hit, it bled.' Mayweather doesn't appear too bothered though, Tweeting on Friday: 'I always have the remedy to do what I have to do to come out on top.'
Manny Pacquiao and Floyd Mayweather meet in Las Vegas on May 2 in 'The Fight of the Century' Filipino Pacquiao was given a speed ball with the face of Floyd Mayweather on it on Monday . Pacquiao then got down to business with a training session at Wild Card Boxing gym . WATCH: Pacquiao sings and directs his own music video for walk-out tune ahead of mega-fight with Mayweather . READ: UFC icon Ronda Rousey backs Pacquiao as Fast and Furious 7 star visits Filipino ahead of Mayweather fight .