Former five-weight champion and future Hall of Famer Floyd Mayweather believes the biggest fight in boxing will soon be between Terence Crawford and Errol Spence Jr.

The welterweight division is one of the most stacked in boxing today with a number of big names fighting at 147 pounds from the likes of World Boxing Association (WBA) and World Boxing Council (WBC) champion Keith Thurman, International Boxing Federation (IBF) champion Spence, Shawn Porter, Danny Garcia, Amir Khan and more.

Crawford (32-0), regarded by many as the pound-for-pound best boxer in the world today, most recently moved up to the weight class after unifying the light welterweight division and will face World Boxing Organization (WBO) champion Jeff Horn for his title on June 9 at the MGM Grand in Las Vegas.

While Thurman (28-0-1) holds two belts and is regarded by some as the current best welterweight in the world, Mayweather, who is no stranger to big-money match-ups, believes a Crawford vs. Spence Jr. fight will soon garner attention as the biggest fight in boxing.

Floyd Mayweather Floyd Mayweather has heaped praise on Terence Crawford and Errol Spence Jr. in the past. Pictured: Apr. 11, 2018; Miami, Boxer Floyd Mayweather Jr. in attendance during the first half between the Miami Heat and the Toronto Raptors at American Airlines Arena. Photo: Jasen Vinlove-USA TODAY Sports

"Honestly speaking, I think soon the biggest fight that's going to be in boxing is Terence Crawford and Errol Spence," Mayweather told FightHype, as quoted on BoxingScene. "That's going to be a huge fight I think in boxing."

"In the future [it's going to be pay-per-view worthy], in the future [it will be pay-per-view] but not right now. I would pay to see it."

Having sparred with Spence Jr. (23-0) in the past, Mayweather also disagrees with the notion that Thurman will provide a bigger test for Crawford.

"No," Mayweather responded regarding Crawford's trainer's view that Thurman is a tougher fight than Spence Jr. "I was 35 when I boxed these guys. I knew Errol had it, and I don’t need to box Terence Crawford to know that he’s got it."

Big welterweight fights have encountered many speed bumps in recent times but Crawford, who expects to be a three-weight world champion in June, is open to a fight with both Spence Jr. and Thurman in the future, recently stating if he and his opponent want to fight each other, it will eventually be booked.

"If a fight needs to be made, it can be made," Crawford said last month. "No matter what the circumstances are, we the fighters need to speak up and make it be known we want to fight each other."

"We go to our promoters and managers and tell them to get it done because at the end of the day, we're the ones fighting, the ones making them the money. So if it's something we really desire to have, I believe it can happen," he said.

For now, "Bud" will have to get past Horn first and while he is the favorite heading into the title fight, the Australian already caused a major upset last year when he controversially defeated Manny Pacquiao via unanimous decision to become champion and will be looking to do the same once again.