By Keith Idec

Amir Khan knows he cannot afford the lapse in concentration that cost him in the second round of his last fight.

Khan already had knocked down Samuel Vargas in the second round of their September 8 bout. Feeling like he was in complete control, Khan let his guard down for a split second.

Before he knew what hit him, Khan was on the seat of his trunks himself.

The British welterweight recovered quickly, dropped Vargas again in the third round and went on to soundly defeat Vargas by unanimous decision six months ago in Birmingham, England. Khan understands, though, that the knockdown he suffered during that win was enough to create even more doubt about a questionable chin that is widely viewed as his biggest disadvantage against Terence Crawford as their April 20 bout approaches.

“That’s the only time I really lost focus in the fight,” Khan explained to BoxingScene.com. “In the fight, I put him down and I was winning the fight quite easily. And, you know, you take your eye off the game, I stood still and he caught me with a good shot over the top and put me down. Sometimes you lose that focus and things like that can happen. I know that against a guy like Crawford I can’t lose my focus one bit because he’s really dangerous, he can hurt me and he can beat me. So, I’m never gonna do that. I’ll be more switched on against Crawford, knowing that it’s a big fight and there’s a lot on the table.”

Crawford (34-0, 25 KOs), of Omaha, Nebraska, is consistently listed as at least a 14-1 favorite over Khan (33-4, 20 KOs) in a 12-round, 147-pound title fight that’ll headline ESPN Pay-Per-View’s telecast from Madison Square Garden in New York.

The 32-year-old Khan has prepared himself much better for this potentially career-changing fight than he did for his last two bouts.

Before beating Colombia’s Vargas (30-5-2, 14 KOs), Khan needed just 39 seconds to knock out Phil Lo Greco last April 21 in Liverpool, England. Khan knocked down Canada’s Lo Greco (28-4, 15 KOs) twice before that brief bout was halted.

“I think the last two fights were just to get me geared up for these big fights,” Khan said. “I need to motivate myself for a fight like this, whereas the last two fights I had it’s hard to motivate yourself against guys that you know that you’re supposed to go in and win against. So, you make a mistake and people put you down.

“I mean, I think this is a fight that I am the underdog. Other than this fight, I think the only other fight was against Canelo when I was the underdog. He was way too big and way too strong. But the other fights I’ve lost, I’ve always been the favorite. That does put a lot of pressure on you. But at the same time, you do take your mind off the game a little bit.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.