Amir Khan is well known for flitting between trainers during his career, but teaming up with the man who masterminded his last defeat is an unlikely switch.
Brian 'Bomac' McIntyre will be the eighth trainer former world champion Khan has had in his corner since turning professional in 2005.
The American trains Terence Crawford, who beat Khan in the sixth round of a WBO welterweight world title defence in April 2019.
Khan, 35, now needs McIntyre to help him find his old spark for the high-voltage welterweight contest against Kell Brook in Manchester on 19 February.
The late Oliver Harrison was in charge for Khan's first 17 fights before being sacked and replaced by the late Dean Powell before Jorge Rubio oversaw Khan's shocking 54-second defeat by Breidis Prescott.
Freddie Roach then trained Khan for his greatest nights, but since they split in 2012 the Bolton boxer has worked with Virgil Hunter, Joe Goossen and Clarence 'Bones' Adams. Under Roach's four-year tutelage, Khan won the WBA super-lightweight title against Andriy Kotelnik and made five winning defences, including a sensational Las Vegas points victory against Marcos Maidana.
The fight against Sheffield's Brook finally takes place when both are considered past their prime. But McIntyre insists Khan can rediscover the Roach years, when he was one of boxing's biggest stars.
"It is so far, so good. Amir is looking good in camp and I am very pleased with where he is right now," McIntyre tells BBC Sport.
"Personally, I think he can get back to where he was. He has been showing signs of Amir Khan from the days when he was fighting Maidana and other guys.
"His hands were fast and his feet were fast. I have been seeing that in the last few sparring sessions.
"If he can do that in the rest of this camp, have a great performance against Brook and win, he can be considered one of the top in what weight class he wants to go to. But I wouldn't advise him to go any higher than welterweight.
"We are making sure he can do the things that we ask of. His hand speed, foot speed and diet has to be right for Amir to perform to his highest peak."
'No doubts' training Khan - McIntyre
Khan's wife Faryal Makhdoom brought the partnership together when she called 'Bomac' at his home in Omaha, Nebraska.
Did he have any doubts about taking Khan on after Crawford accused him of quitting in their fight at Madison Square Garden?
"Not at all," adds McIntyre, who also saw Brook close up when Crawford beat him 15 months ago.
"What I wanted to do was challenge myself and my team to see if we can get Amir back to where he used to be.
"The first thing we did was get Amir into the shape so he can accomplish what he wants to do in the ring.
"That was the most important thing. Getting his body together, getting his diet together, bringing his weight down and making sure he can move on his feet.
"Once you get to that point we start to go over Brook more. I have studied Brook a lot and he won't be no different from this time to last time."
'Terence fought both, dominated both and he knows best'
The undefeated Crawford, 34, has helped in camp too, sparring with Khan in Omaha and Colorado Springs, where the team is based at the foot of the Rocky Mountains.
McIntyre adds: "From what Terence told me, he thought Amir was looking better.
"I respect those thoughts and comments. You want to hear things like that and what he needs to do more from the best in the world.
"You have to understand that Terence fought Amir and Brook, dominated both and he knows best."
Khan has also called on help from his relative and fighter Abdul Khan. At the very start of his professional career, Abdul will fight on the Khan-Brook undercard. After training in Omaha with Amir, Abdul says he was blown away by his cousin's focus under McIntyre.
"Amir has put in so much effort," he reveals.
"I felt like he was rolling back the years - he was locked in to what he was doing and totally focused, with his mind fully on the job. He's ready to go and knock Kell Brook out."
'Nobody knows who Amir is and wants to take pictures'
Olympic silver medallist Khan, who has won 34 of his 39 professional fights, has rarely trained at home in Britain.
That came as a relief to McIntyre, who appreciates how much the contest - where all 20,000 tickets were sold in just 10 minutes - means to British fight fans.
McIntyre explained: "I am glad that we are over here training in the middle of the United States. We have total privacy.
"We can walk into the 24 Hour Fitness gym and Walmart where nobody will know us.
"Nobody knows who Amir is and wants to take pictures and autographs and things of that nature.
"I know the fight is one of the biggest in Britain and I'm excited for my team and myself to be a part of it.
"Once we get this win, it will go down in history that our team came over there, upset Kell Brook and Amir looked like he did in 2010, 2011 and 2012."
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