Virgil Hunter says Amir Khan is back on track for world title glory ahead of Saturday's bout with Julio Diaz.
Hunter, who replaced Freddie Roach as Khan's trainer, is confident the Briton can regain his former status as former world champion despite back-to-back losses to Lamont Peterson and Danny Garcia in world title fights.
The Bolton fighter began the process with victory over Carlos Molina last December and he takes what he hopes is the next step against Mexican Diaz on in Sheffield with Hunter insisting Khan has learnt from his mistakes.
Hunter said: "When he came to us we had concerns about his past fights. We had him properly assessed so we could begin the necessary process to correct the problems.
"All you ask for is to learn from mistakes, and he will, but there were mistakes made against him too.
"He has gone into fights outweighed by 12 or 13 pounds and this is something that shouldn't have happened.
"If he is the king of the hill, he dictates the terms. But there is no doubt at all he can be world champion again.
"He is in great physical shape, he is still young, he has strength of character. He is the only fighter I have known personally - and I've known some - in the world of boxing who hasn't been affected by a knockout.
"His troubles have been connected to mistakes and not that the other guy was better than him. Because of that, he is still intact confidence-wise."
Khan takes on Diaz in a non-title bout set at a "catch weight" of 143 pounds, a mark between super lightweight and welterweight.
It will be the heaviest Khan has fought at while California-based Diaz, himself a former world lightweight champion, is coming down slightly after recent welterweight fights.
Diaz also feels the fight can propel him back into the world title frame.
Diaz said: "I know I have a big fight in front of me, against a tough warrior. He has fought fighters when he has been out on his feet but he has finished them. Not a lot of fighters can do that. He has the heart of a lion.
"But I am ready for that. I came to fight and I have trained hard. Amir Khan is my ticket and I am going to get it."
Name the outcome in Khan v Diaz
Khan by KO
Diaz by KO