Otto Wallin was more than a little surprised when Anthony Joshua chose to fight him Saturday night.

Joshua lost back-to-back bouts to the last left-handed opponent he faced, Oleksandr Usyk. And if Joshua beats Wallin, the former IBF/IBO/WBA/WBO heavyweight champion is expected to battle a right-handed opponent, Deontay Wilder, next, reportedly March 9.

The 34-year-old Joshua will also work with another new trainer, Ben Davison, when he squares off with Wallin in the main event of the “Day of Reckoning” pay-per-view show at Kingdom Arena in Riyadh, Saudi Arabia.

“It’s kind of a short notice fight,” Wallin told BoxingScene.com, “he’s fighting a southpaw again, he’s got a new trainer and I think that’s a lot of things against him. I don’t know what they were thinking, but I’m happy about it. Usyk is, of course, a really, really good fighter, one of the best. But I’m also bigger than [Usyk], I’m a good southpaw, I know how to use that and that’s just another thing that’s in my favor, I think.”

Ukraine’s Usyk (21-0, 14 KOs) outboxed Joshua and won their first fight by unanimous decision in September 2021 at Tottenham Hotspur Stadium in London. Joshua (26-3, 23 KOs) was more competitive during their 12-round rematch, but Usyk out-pointed him by split decision in August 2022 at Jeddah Superdome in Jeddah, Saudi Arabia.

“I’ve been watching those fights, the [Andy] Ruiz fight and I know Joshua pretty well,” Wallin said. “Yeah, there are some things there and it’s kind of funny because Usyk is the only one to beat [Murat] Gassiev [before] I fought Gassiev. I was watching that fight a lot and now I’m watching him fight Joshua. We’re both southpaws, so there are some things I take from that. I also take confidence from it, that he has already been beat by a southpaw twice.”

Sweden’s Wallin (26-1, 14 KOs, 1 NC) believes the insistence of Joshua’s team to insert rematch clauses in their contracts signifies the British superstar’s lack of confidence entering their 12-round, non-title fight.

“It’s a fight that I really want and I believe I’m gonna win the fight,” Wallin said. “I beat him once, I can beat him again. And then after those two fights, I should be in line to fight for any title. I mean, I wish there was no rematch clause, but it is what it is. He’s not even a champion right now, so why would they have a rematch clause? It’s kind of funny, but you know, boxing works that way and sometimes to get these big opportunities there’s some things you have to agree on that you don’t want to.”

Wallin’s split-decision victory over Russia’s Gassiev (30-2, 23 KOs) on September 30 in Antalya, Turkey earned him the number two position in the IBF’s rankings. Croatian contender Filip Hrgovic (16-0, 13 KOs), who will square off against Australian underdog Mark DeMori (41-2-2, 36 KOs) on the Joshua-Wallin undercard, is ranked first by the IBF.

If Usyk, who is scheduled to battle WBC champ Tyson Fury (34-0-1, 24 KOs) on February 17 at Kingdom Arena, eventually vacates the IBF belt, the IBF would likely order its number one and number two contenders to fight for its unclaimed championship.

“This fight would never happen if I didn’t have the number two spot with the IBF,” Wallin said. “That’s obviously what they’re going for. They think that if he beats me he gets the number two spot in the IBF, and he’d be in line to fight Hrgovic. It’s likely that he would fight Hrgovic for the title, so that’s what they’re going for. But I’m surprised. Of course, they had to put a rematch clause in there because they’re scared of him losing. It is what it is.”

Joshua-Wallin undercard coverage is scheduled to begin at 4 p.m. GMT in the United Kingdom (£19.99) and 11 a.m. ET in the United States ($39.99). Wilder (43-2-1, 42 KOs), a former WBC champ from Tuscaloosa, Alabama, will encounter ex-WBO champ Joseph Parker (33-3, 23 KOs), of South Auckland, New Zealand, in the 12-round co-feature.

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