Bob Arum wasn’t the least bit surprised Andy Ruiz Jr. was overweight for his rematch against Anthony Joshua.

Ruiz’s weight woes and his overall lack of discipline often frustrated Arum when his company, Top Rank Inc., promoted the former heavyweight champion. Now that those troubles have helped thrust another heavyweight he promotes into a title fight with Joshua, Arum also won’t be surprised if Kubrat Pulev upsets Joshua.

Pulev (28-1, 14 KOs), who’s co-promoted by Top Rank, is the mandatory challenger for Joshua’s IBF heavyweight title. Eddie Hearn, Joshua’s promoter, said after Joshua out-pointed Ruiz in their immediate rematch Saturday night in Diriyah, Saudi Arabia, that Pulev probably will be Joshua’s next opponent.

“I think Pulev can beat Joshua,” Arum told BoxingScene.com. “I really believe that. Pulev is gonna come in in great, great shape. He’s gonna pressure Joshua. He takes a great punch. I think he has a hell of a shot with Joshua. So, we’re pushing for that fight.”

Pulev, 38, has lost only to former champion Wladimir Klitschko, who knocked out Pulev in the fifth round of their November 2014 fight. Bulgaria’s Pulev was supposed to challenge a then-unbeaten Joshua in October 2017, but Pulev suffered a shoulder injury and was replaced on short notice by Carlos Takam.

England’s Joshua (23-1, 21 KOs) also has a mandatory defense of his WBO championship that is due. Former undisputed cruiserweight champion Oleksandr Usyk (17-0, 13 KOs) is the WBO’s mandatory challenger for that title, but Arum is confident Joshua-Pulev will take place before Joshua-Usyk.

“We have it in writing from the IBF that the winner of the [Joshua-Ruiz rematch] would have to fight Pulev by the end of May,” Arum explained. “Not only that, but it had to be the next fight [for Joshua]. That’s what they said, and we have it in writing. We fought for it, and they finally gave it to us in writing about two months ago. That’s a binding contract, and the other side agreed to that. When Eddie’s ready, we’ll sit with him and we’ll try to figure out what the purses are and where the fight’s gonna be held.”

Despite his technical-knockout loss to Ruiz six months ago, Joshua remains a huge star in the United Kingdom. Hearn said the brand-new Tottenham Hotspur Stadium in London could be the site for Joshua’s next bout because there are few dates available in the spring at London’s Wembley Stadium, to which Joshua twice has drawn capacity crowds in excess of 80,000.

“England has a couple of things going for it – they’ll get a great gate and they’ll do very high pay-per-view numbers,” Arum said. “In the United States, I don’t think [Joshua-Pulev] would do a great gate. You know, Joshua, yeah, maybe he’ll bring some Brits over here to watch the fight in the United States. Pay-per-view would be good in the United States, but we’d have to pencil it out. It may very well be that the United States, economically, is more feasible. But Pulev is not concerned where the fight’s gonna be. He just wants to get in the ring with Joshua. And because Joshua’s the senior partner, because he’s the champion, pretty much [Joshua will] determine where the site of the fight should be.” 

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.