One knowledgeable observer is sure that the next fight of the century will live up to the hype.

Canelo Alvarez will defend his undisputed super middleweight championship against Terence Crawford on Sept. 13 at Allegiant Stadium in Las Vegas on Netflix, a captivating — perhaps historic — matchup that could give a significant boost to the legacy of the winner.

Andy Lee, former middleweight champion and one of boxing’s best trainers, believes that the fighters' skill sets will allow for the matchup to meet expectations.

“What a fight,” Lee told The Ring’s Louis Hart. “It’s very hard to pick a winner. No one really knows the skill and competitiveness and ringcraft of Crawford. You can say the same things about Canelo, but he has the size [advantage].

"I saw Crawford in New York when Hamzah [Sheeraz] fought [Edgar] Berlanga, and he doesn’t look too small anymore. He's filled out a lot [and] looked quite big. It's a great fight. They’re equally matched in skill.

"When you see how skillful both fighters are, the tricks they have and how they fight, it should be up there with the best fights we can remember.”

Crawford (41-0, 31 KOs), a two-division undisputed champion, had fought his previoius eight fights at the welterweight limit of 147 pounds before moving up to 154 and defeating Israil Madrimov (10-2-1, 7 KOs) by unanimous decision last August to become the WBA junior middleweight titleholder.

The 37-year-old from Nebraska had stopped 11 straight opponents before winning a close decision over Madrimov.

Arguably, the biggest question mark heading into the bout is how Crawford will handle jumping two more divisions to face a full-fledged 168-pounder in Alvarez. Lee believes that the weight will not hinder Crawford, who is a four-division beltholder.

“You’ll be stronger,” Lee said. “You’ll have more of everything. I don’t think it’s going to affect Crawford.”

Alvarez (63-2-2, 39 KOs), who has also won titles in four divisions, is 11-0 with four knockouts at super middleweight. The 35-year-old from Mexico is coming off a unanimous decision victory over William Scull on May 3 in a less-than-compelling affair to become the undisputed champion for a second time.

While Alvarez has shown signs of slowing down in his recent fights, Lee believes the challenge that Crawford presents will bring out the best in him.

“[Alvarez has a] great jab [and is] a skillful body puncher [and] counterpuncher,” Lee said. “People are not giving him respect because of his last performance. Trust me, he’ll turn up and he's a competitor, too.

"That's the great thing about these guys, they're winners. And I can’t wait to see that fight.”