Former 140-pound titleholder Amir Khan has declared himself to be "ready for this challenge" of making his welterweight debut against Luis Collazo on the undercard of the May 3 clash headlined by Floyd Mayweather Jr.'s defense of his RING, WBC and WBA 147-pound belts against Marcos Maidana at the MGM Grand in Las Vegas on Showtime Pay Per View.

"Amir Khan and Luis Collazo are aggressive boxers who deliver excitement and fan-friendly action in every fight," said Stephen Espinoza, executive vice president and general manager, Showtime Sports.

"With the addition of this main event-caliber co-feature bout, boxing's biggest night of the year has become even bigger. Mayweather vs. Maidana and Khan vs. Collazo is a spectacular one-two punch for boxing fans."

On the heels of an earlier announcement by Golden Boy Promotions CEO Richard Schaefer to RingTV.com, Khan stated, "I will be fighting Luis Collazo on May 3rd Las Vegas" on his Twitter account.

"I'm looking forward to fighting in Las Vegas once again and my intention on May 3 is to make a statement that I belong on this big stage," said Khan, in a prepared statement billing the event as "The Moment."

"Luis Collazo might be coming off of a big win but I am in incredible shape and am ready for this challenge. A win on May 3 is what I need to prove that I truly am one of the best welterweights in the sport."

Khan will be looking for his third straight victory in as many fights under trainer Virgil Hunter, who replaced Freddie Roach after Khan was stopped by Danny Garcia in July 2012.

Before facing Garcia, Khan had lost a disputed split-decision to current IBF 140-pound beltholder Lamont Peterson in December of 2011.

Khan rebounded with triumphs in his last two fights by 10th-round knockout over Carlos Molina (a California-based lightweight prospect not to be confused with the IBF junior middleweight titleholder of the same name) in December of 2012 and by unanimous decision over former titleholder Julio Diaz last July.

"Putting a fight of this magnitude like Khan-Collazo is not exactly cheap," said Schaefer during an interview with RingTV.com. "It just shows Floyd Mayweather's continued commitment to put together these kinds of cards. So it's going to be a terrific night of boxing on May 3."

Collazo, who turns 33 in April, knocked Victor Ortiz out in their second round in January and has called out Khan.

"Both Amir Khan and Luis Collazo have made it known that they want a shot at the winner of the fight between Floyd Mayweather and Marcos Maidana," said Schaefer in a prepared statement.

"So what better way for them to prove that they're next in line than by fighting on 'The Moment' card on May 3? These are two exciting former world champions and this fight has the potential to steal the show."