Amir Khan is confident a return to trainer Virgil Hunter will help him dethrone Terence Crawford.
Hunter was struck down with illness last year, forcing Khan to team up with Joe Goosen.
The Brit blasted out Phil Lo Greco in just 39 seconds last April before climbing off the canvas to outpoint Samuel Vargas five months later.
Khan has returned to San Francisco to be reunited with Hunter ahead of his date with Crawford on April 20.
And he said: "Training is going really well. I am here in San Francisco and really liked getting back with Virgil.
Terence Crawford breaks down Amir Khan fight ahead of world title clash
"I really believe he knows me better than anyone else – than any other trainer. In fact, I was with Joe Goossen because Virgil was a little sick, and I had to make a quick change.
"I have had my best performances in boxing with Virgil, great wins, and I couldn’t wait to join with him again. Since we began camp, everything has been going really well.
"We are sparring hard, training hard, and going to be in great condition because we know that Terence is a great fighter.
"I respect the way he fights, and I respect that he’s done it again and again and he’s one of the best pound-for-pound fighters. Also, my conditioning coach Tony Brady is here. The camp I have had is great and I’m happy with it."
Khan has not fought at world level since he was brutally knocked out by Canelo Alvarez in 2016.
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But he believes he can upset Crawford next month.
He added: "I am not taking this fight lightly and I am not taking it to be a number because I know I can win this fight with my boxing skills, being smart, and I can go in there and cause a big upset.
"I know I have a lot against me, but this is where I like to be. This is where I like to be because I am the underdog. I am at my best when people are looking over me.
"This is the time where I can come and prove everybody wrong, and I feel that timing-wise, this is the perfect timing for this fight. I always wanted to be up there in the pound-for-pound rankings.
"I am 32 now and I feel strong physically and mentally. I am prepared for this fight, so this is perfect timing for me to take this fight and win the fight as well."
