The Mexican superstar will challenge for the WBA light heavyweight world title against Dmitry Bivol in Las Vegas on Saturday night.
It will take place at the 20,000 capacity T-Mobile Arena situated on Park Avenue.
Russian boxer Bivol, 31, has only had 19 fights since turning pro and will go in as the underdog against pound-for-pound king Canelo Alvarez.
But with 11 KOs from those fights, Bivol and his camp will be confident of upsetting the odds and bringing his belt back to Russia.
Even so, Canelo has already cast his mind to the future, as he has apparently also set his sights on Usyk’s heavyweight titles as well according to promoter Eddie Hearn.
The 31-year-old Mexican only has two draws on his record, one against Kazakh legend Gennady Golovkin and another albeit years ago against Jorge Juarez.
He has won 57 times with 39 KOs, and one loss to Floyd Mayweather.
And former heavyweight world champion Rahman reckons Canelo, who turns 32 in July, would win a hypothetical fantasy fight against Usyk – but on one condition.
Rahman, 49, told FightHype.com: “Canelo? I’d love to see him fight Usyk at 201lbs.
“I think he’s got a chance.
“I actually think he might be the favourite.”
Asked if Canelo is too small to fight at heavyweight, he added: “Yeah, I would think that, but you’ll notice, I said 201.
“Now Usyk has to lose weight, lose muscle to come down, and Canelo would be gaining muscle.
“Canelo can box. Canelo spars heavyweights all the time.
“Usyk isn’t one of the biggest punching heavyweights. He wasn’t a big-punching cruiserweight. So, I give Canelo a shot at 201 of winning the unified heavyweight championship of the world at 201.
“I give him a shot. I think he can. Even if he doesn’t, all the strengths that Usyk has, Canelo has.
“Canelo has got an iron chin. Usyk isn’t going to hurt him, so I give him a chance. In fact, I might make him the favourite.
“Yeah, I’m picking him.”