Amir Khan knows he must bring his ‘A’ game to come through against WBO welterweight champion Terence Crawford at Madison Square Garden on 20 April.

The 32-year-old turned down terms to finally meet British rival Kell Brook and instead will head to New York to face what will be a formidable challenge against one of the world’s finest fighters.

Khan has been training again with the respected Virgil Hunter, having delivered two victories working alongside Joe Goosen.

The Bolton fighter recovered from a second-round knockdown to beat Colombian Samuel Vargas on points in his last contest during September 2018 in Birmingham.

Khan intends to step things up again when he walks out against 31-year-old southpaw Crawford, who in 2017 unified all four light-welterweight world titles.

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“We are training hard and sparring hard. I know Terence is a up there with the best pound-for-pound fighters and I respect what he has done. I am not taking this fight lightly,” Khan said in a conference call on Tuesday.

“But I know I can win this fight with my boxing skills, being smart and cause an upset. When I am an underdog, I perform at my best.

“It is the perfect timing for this, I am at the peak of my career now at 32. I feel strong physically and am mentally prepared for this fight.

“When this fight was put to me, a pay-per-view fight, I knew it was going to be a big fight and was a fight I want.”

Khan added: “People might feel from my last performance against Vargas, I am going to be the same – but I know that was a very bad performance, it was not me.

“It is hard to motivate yourself against guys where you are supposed to win, all you have to do is turn up.

“In this fight, I have to bring my A-game, to make sure I cannot make any mistakes, go into it as the underdog – but to prove myself I am going to win this fight.”

The New York showdown could yet prove a defining fight for Khan, who last held a world title in 2012 – and suffered a knockout defeat in his WBC middleweight contest against Saul Canelo Alvarez in Las Vegas two-and-a-half years ago.

The prospect of a unfinished business and a clash with Brook, though, continues to rumble on.

Crawford unified all four light-welterweight world titles in 2017 (Getty)

“I don’t know if that fight is still going to be there. I chose this fight over that one,” Khan said.

“I know I have seen numerous times in the media, (Brook’s promoter) Eddie (Hearn) saying the fight is dead now, it is not going to happen again.

“Look, who knows? Time will tell. I am taking it fight by fight, so let’s get this one out of the way first, then we will take it from there."