The reigning welterweight king recently underwent surgery earlier this year to repair ligament damage he suffered in his right hand three weeks before his rematch with Colby Covington last November.
Usman, 34, is now 20-1 as a MMA fighter having most recently defeated Covington, also 34, on points, almost two years after knocking out his fellow American in December 2019.
It means he has beaten every opponent he has faced inside the octagon, including BJJ black belt Gilbert Burns, 35, inaugural ‘BMF’ titleholder Jorge Masvidal, 37, and former UFC welterweight champion Tyron Woodley, 40.
Edwards and Chimaev meanwhile are ranked No2 and No3 respectively according to the official UFC.com website.
And St-Pierre – considered by many as one of the greatest MMA fighters of all time – believes they could both cause a few problems for the Nigerian Nightmare.
He told MMA News: “I believe there’s a lot of guys that can beat Usman.
“I do believe personally Usman is the best right now in the division but that doesn’t mean he is invincible.
“He needs to always stay on top of the game. It’s hard to be champion and it’s even harder to stay champion. I’m sure if you ask Usman, he’ll tell you the same thing.
“He’s on a tear right now, he looks phenomenal but there’s a lot of guys that can give him a lot of trouble like Khamzat Chimaev. Leon Edwards, maybe. Usman so far has been a puzzle that no one is able to solve.
“He’s incredible but he needs to stay focused to make sure he never underestimates nobody and trains for every fight like it’s the hardest fight he’s ever had.”
“Nobody’s invincible, everybody can be beat. It’s not the best fighter that wins the fight very often.
“It’s the question about the fighter that fights the best the night of the fight and there’s a lot of things that can influence the result of a fight.”
Usman, who is currently recovering from surgery, is eyeing a return to action this summer which he hopes will be a headline spot on International Fight Week in July.
Speaking in an interview with The Sun last month, he said: “That’s what I want.
“But of course, I have to take the necessary measures to make sure that I prepare [for the fight properly].
“And my hand is something that; these are the money makers. So I have to make sure that it’s healed completely before actually jumping back in there.
“I have a lot on the line, a lot to lose. Not just the belt and money, but also my health as well.
“And the functionality of my hand permanently.
“So I have to make sure that I wait the appropriate time and listen to the doctors here and get back to work when it’s time.
“Leon is much sharper with his striking. He has excellent striking. I mean, let’s just be honest.
“We saw it in the fight with Nate Diaz. He tortured him for four-and-a-half rounds.
“And then Nate Diaz did what Nate Diaz does best, come in there and land that shot and steal all the glory.
“You forgot Leon Edwards won that fight, right? So I think Leon is much improved.
“His grappling is much improved, his wrestling is much improved, but I’m also much improved.”