LAS VEGAS– In Saturday night's clash of former titleholders at the MGM Grand, southpaw Luis Collazo will represent several firsts for Amir Khan.

A 27-year-old from Bolton, England, Khan (28-3, 19 knockouts) will have been out of the ring for more than a year for the first time in his career and will be debuting both at 147 pounds and at the MGM, although he has fought on three previous occasions in Las Vegas, Nevada all at the Mandalay Bay Hotel.

"It’s going to be a great event, my first time fighting at the MGM Grand, not in Las Vegas but at the venue. I worked very hard; I feel healthy and strong at 147," said Khan, who will appear against Collazo on an undercard whose main event matches RING and WBC welterweight champion Floyd Mayweather against WBA counterpart Marcos Maidana.

Khan's first fight in Las Vegas was a unanimous decision over over Maidana, whom he dropped in the first round in December 2010. Khan scored a fifth-round stoppage over Zab Judah during his next visit in July 2011 but was knocked out himself in the fourth round of his last appearance by RING, WBA and WBC 140-pound champion Danny Garcia in July 2012.

A win over Collazo (35-5, 18 KOs), 33, from Brooklyn, N.Y., could earn Khan a shot with Mayweather that eluded him when Mayweather elected to face Maidana instead of him.

But Khan is in tough against Collazo, who has gone 6-1 with four knockout victories in his past seven fights and is coming off January's second-round knockout of former titleholder Victor Ortiz.

"I’m not looking past Collazo. He's a good, strong fighter. We just want to put on a show and the best man will win. Collazo is definitely a good opponent. In his last fight, he proved himself by knocking out Victor Ortiz," said Khan, during a Tuesday interview in the VIP room of the MGM Grand. "Ortiz was a big name and a good fighter and he knocked him out in the second round. Yeah, he definitely earned his way into this fight."

Since stopping Judah, Khan said he has been physically draining himself to make 140 pounds and after falling to Garcia, left trainer Freddie Roach in favor of Virgil Hunter for his next two fights, resulting in a 10th-round stoppage over California-based Carlos Molina in December 2012. The win over Molina was followed by a unanimous decision over former titleholder Julio Diaz, who dropped him in the fourth round in his last fight on April 27.

"I think the move to 147 was a good move. I have been thinking about it since a long time ago. I should have done it probably a year or two ago. It really hit me in the Diaz fight. I just felt like I just had no energy. A day before the weigh-in, I was like, 14 pounds overweight and I thought, 'I just can't keep doing this to my body,'" said Khan, who said he was "about five pounds over" on Tuesday.

"I was killing myself making the weight, so here we are now. People say that I'm looking past Luis Collazo and looking at a Mayweather fight or other opponents but I'm not looking past this fight because this is a big fight for me. But if I lose this fight, I can forget about the $12 million. So I have to win this fight against Luis Collazo. Luis brings a lot to the table."

Collazo is a career welterweight who is 4-0 with two stoppage wins since falling by 10-round unanimous decision to Freddy Hernandez, who dropped him in the eighth round in October 2011.

Collazo split decisioned Jose Antonio Rivera for the WBA's 147-pound belt in April 2005 and stopped Miguel Angel Gonzalez in the seventh round of his first defense in August of that year. He lost the title to Ricky Hatton in a disputed unanimous decision after being floored in their first round in May 2006. From there, Collazo went 3-2 with two knockout wins over his next five fights, falling by unanimous decision to Shane Mosley and Andre Berto in February 2007 and January 2009, respectively.

"He's been in there with a lot of guys like Ricky Hatton, Shane Mosley, Berto and he's given them a lot of trouble. He's not going to be easy. He's got a game style and he likes to come forward and he's a southpaw and he's awkward," said Khan. "At times, he boxes more. He doesn't have great power but he's quite slick. I've worked hard for the best Luis Collazo to be in the ring with me on Saturday night. We've trained really hard for this fight and we've not left anything out. We're going to be ready."