Saul 'Canelo' Alvarez "wouldn’t be able to do" many of his trademark techniques in a fight against the retired great Andre Ward, says Virgil Hunter.
Ward hung up his gloves undefeated with 32 victories in 2017, amassing world titles at super-middleweight and light-heavyweight and establishing himself as the No 1 pound-for-pound boxer on the planet.
Canelo has inherited that moniker as boxing's top fighter but Ward was on a different level, his former trainer Hunter insists.
"I don't like to say who would win. But a lot of the things that Canelo does, he wouldn't be able to do to Dre," Hunter tells Sky Sports.
"The things he's able to do? He would not be able to do it to Dre. He would have to become a completely different fighter.
"Whoever adapted mentally, whoever adjusted over the course of a fight, whoever was in tune to the other's rhythm would have the greater chance of winning.
"Once he retired, I knew he would stay retired. We discussed early in his career that he would go out on top.
"He is a Hall of Famer. Let's leave it at that. Nobody can talk about a loss.
"He may ask himself if he made the right decision at the right time.
"But I tell him: 'Don't ever question your decisions particularly if there are no questions left unanswered'.
"All people can do is wonder. It is not the public's decision whether you retired late or early.
"It's hard to find guys who did it [his] way so he stands alone."
Ward defeated Carl Froch and Mikkel Kessler at super-middleweight before stepping up to end Sergey Kovalev's undefeated reign as light-heavyweight champion with back-to-back wins.
Canelo's path to his WBA, WBC and WBO super-middleweight titles was "not that difficult" in comparison to Ward's, says Hunter.
Canelo wants to face IBF champion Caleb Plant later this year in a battle to become undisputed champion.
"Plant does bring some tools to the fight. Whether or not they are enough to hold Canelo off? It remains to be seen," says Hunter.
"Plant will put up a better fight than Saunders because he is taller and more comfortable at the weight.
"Right now Canelo has so many options. It is difficult to find one standout guy who would beat him.
"I would have him competitive in any fight, even light-heavyweight against Dmitry Bivol or Artur Beterbiev.
"Beterbiev's age would give [Canelo] a chance. Bivol seems to fight at one-pace, he doesn't take it to the next level. He hasn't been busy.
"Canelo has an advantage to call his own shots to stay busy. Although it can back-fire - stamina-wise, in the Billy Joe Saunders fight, I felt that he started to tire before he landed that punch.
"Saunders' feints and antics were mentally getting to Canelo which subjected him to physical fatigue.
"If that punch hadn't have landed, it would have got a lot more interesting, based on his fatigue.
"But there is not a fighter at super-middleweight or light-heavyweight that has a sure shot of beating him, but there are fighters you want him to compete with.
"David Benavidez, for example, is a strong guy who won't back down with hand speed, height and reach."
Can Joshua Buatsi reach similar heights?
Veteran trainer Hunter will be in Joshua Buatsi's corner for the first time on Saturday night, live on Sky Sports, against Daniel Blenda Dos Santos.
"It's impossible to meet the expectations of what Andre was," Hunter says about Buatsi.
"I had Andre since he was nine years old so he was subjected to my philosophies, to my teachings, that a lot of fighters who come to me later on don't get.
"Is there any comparison? His work ethic is on a similar path. His focus is getting there.
"But it's unfair to compare. Joshua has his own style and I have to adjust to him instead of trying to make him into Andre Ward, because that will never happen.
"He has to go about it his own way. His own path. And I have to recognise that path."