By Edward Chaykovsky

Virgil Hunter, trainer for British star Amir Khan (30-3, 19KOs), is not on board with the critics who believe WBC/WBA welterweight and junior middleweight champion Floyd Mayweather Jr. (47-0, 26KOs) is "old" and fighting like a "shot" boxer.

Khan is trying to get Mayweather in the ring in the first half of 2015. Even Khan has questioned Mayweather's abilities.

Hunter admits Mayweather, who is closer to 40, is no longer the same fighter who was closer to 20 or even closer to 30 - but he sees Mayweather's current fighting style as being physical adjustments to the changes in his body - similar to the reinvented fighting style of Bernard Hopkins.

"He's not the same guy the you saw five years ago or six years ago. He's the guy that now continuously reinvents himself. A fighter can only reinvent himself when he has some attributes in place, from a physical point and also from a mental point. Floyd's IQ, being at the very top in boxing, and his physical ability toned and sharpened from years an years of repetitions - him reinventing himself is just an adjustment to the times. But everything else is intact," Hunter told On The Ropes Boxing Radio .

"He might not hit you with a jab and bring a hook off of it. He might be reversed, he might hit you with one or the other. It's like Bernard reinventing himself. Only in boxing does a guy get ridiculed for not being the same guy that he was in his 20's. That's what great athletes do. When you have one thing starting to slip, you bring another ingredient into it that benefits your skill as a fighter. And Floyd has proven that."