LAS VEGAS (AP) -- Amir Khan got a fight in the weight division he wanted and on the card he wanted.
He just didn't get the opponent he wanted.
A loser in the sweepstakes to fight Floyd Mayweather Jr., Khan had to settle for the next best thing: A spot on top of the undercard Saturday night in Mayweather's welterweight title fight against Marcos Maidana.
''I would have loved to fight Floyd Mayweather, but I believe it's really for the best,'' Khan said. ''It gives me a chance to get to 147 and feel my way.''
Khan moves up to welterweight to fight former champion Luis Collazo in a fight that will do more than just test his ability at the higher weight. It could also serve as an audition for a possible fight against Mayweather in September, assuming Mayweather does what oddsmakers here expect and beats Maidana.
The silver medalist for England in the 2004 Olympics is in desperate need of a big win to kick start a stalled career. Khan will be fighting for the first time in more than a year, and he struggled in his last outing last April to beat Julio Diaz in Sheffield, England.
''People always remember you from your last fight, and my last fight wasn't my best,'' Khan said. ''We want to steal the show and have fans talking about our fight.''
Khan was more than just in the running to fight Mayweather at the MGM Grand hotel. He and Maidana were the two finalists in an online poll Mayweather conducted to have fans pick his opponent.
Fans picked Khan, but Mayweather went with Maidana anyway. The decision stung even more because Khan had passed on a welterweight title fight with Devon Alexander in December so he wouldn't jeopardize his shot at Mayweather.
Khan (28-3, 19 knockouts) was philosophical about not getting the Mayweather fight, saying it gives him more time to work with new trainer Virgil Hunter while also adapting to a new weight class. But he recognizes Mayweather can't be on his mind when he enters the ring before a capacity crowd waiting to see Mayweather fight Maidana.
''People are saying I'm looking past Luis Collazo for Floyd Mayweather,'' Khan said. ''If I lose this fight, there is no fight with Floyd.''
Collazo is not the kind of fighter anyone can overlook, though Khan is a 3-1 favorite in this city's sports books. Collazo (35-5, 18 knockouts) is a former two-time champion coming off an impressive knockout of Victor Ortiz, who in 2006 gave Khan's countryman Ricky Hatton a tough fight before losing a decision.
Khan, who beat Maidana in 2011, has been working with Hunter his last two fights after splitting with Freddie Roach. He said he has improved his defense and gotten away from the wild brawling that has cost him at critical times in his career.
''I used to take silly shots; I used to jump onto a lot of the shots, which I believe are probably twice as hard as when you do get hit,'' Khan said. ''So we've worked on being smart, being patient, using the defense and the offense at the right time. He's making me understand the sport of boxing.''
Despite losing out on fighting Mayweather, Khan is getting the same $1.5 million payday that Maidana will receive. It could be much bigger in his next fight should he feel comfortable at his new weight and look good against Collazo.
''I'm so much stronger, I haven't killed myself making weight like in the past,'' Khan said. ''It used to be the last seven, eight pounds were the hardest. I'd stop eating and drinking. Now I can eat what I want when I want.''