Hall of Fame promoter Bob Arum apparently does not give Jermell Charlo much of a chance against Canelo Alvarez.

Charlo, the undisputed junior middleweight champion from Houston, Texas, will be moving up two weight classes to challenge Alvarez for his four 168-pound titles Sept. 30 in Las Vegas.

The announcement took the boxing world by surprise as most pundits and fans believed Charlo’s brother, the middleweight titlist Jermall, would get the nod to face the Mexican superstar. Alvarez signed a three-fight deal with Premier Boxing Champions.

The intriguing bout features a rarity in the sport: two fighters who are undisputed in different weight classes.

But apparently for that reason, Arum, the head of Top Rank, does not see the contest as a competitive one, saying recently that he expects Alvarez to stop Charlo inside the distance. Top Rank is not affiliated with either fighter.

“Well, Canelo will beat him easy,” Arum told Little Giant Boxing in Los Angeles during a screening of the new HBO documentary about the life of Oscar De La Hoya. “Charlo is not…little Charlo? No. Canelo will probably knock him out in six or seven rounds.”

Charlo, 33, has never fought beyond the 154-pound division as a professional. Alvarez, on the other hand, has won titles at 154, 160, 168, and 175. Nevertheless, Charlo boasts advantages in height and reach.

Alvarez, 33, is coming off a tougher-than-expected unanimous decision over John Ryder in May in Alvarez’s hometown of Guadalajara.

Charlo has not fought since May of last year when he knocked out Brian Castano to become the undisputed junior middleweight champion. His scheduled mandatory defense against Australia’s Tim Tszyu had to be postponed after he broke his hand during training camp. The plan was to reschedule the fight for this summer but after the Alvarez fight cropped up for Charlo, the fighters went their separate ways.

Sean Nam is the author of Murder on Federal Street: Tyrone Everett, the Black Mafia, and the Last Golden Age of Philadelphia Boxing.