LAS VEGAS – Otto Wallin’s promoter realizes his fighter is unknown among American boxing fans.

Complete anonymity and his lack of experience against championship-caliber opposition are among the reasons England’s Fury is listed as a 25-1 favorite over Wallin at the MGM Grand sports book. According to Dmitriy Salita, the public’s perception of Wallin is about the change dramatically.

Salita, whose company promotes Wallin (20-0, 13 KOs, 1 NC), is sure the Swedish southpaw is prepared to pull off what would be the second epic upset within the heavyweight division in the past three months. Wallin is a slightly bigger underdog than Andy Ruiz Jr. was when he knocked down Anthony Joshua four times and stopped him in the seventh round June 1 at Madison Square Garden.

“Otto’s an undefeated, world-rated fighter,” Salita said Wednesday during a press conference at MGM Grand. “He has beaten everyone put in front of him. He’s been training in the United States with Joey Gamache – who’s a former world champion, great trainer, great teacher – for over four years. So, for all the people who say he hasn’t really fought in the United States, he’s had the experience of training in the United States, boxing and sparring with some of the best fighters in the world. And he’s 20-0. In the United States, not a lot of people know who he is. But on Sunday morning, he’s gonna be the biggest name in sports.”

Defeating Fury (28-0-1, 20 KOs), who’s considered the lineal heavyweight champion, indeed would elevate the 6-feet-5, 230-pound Wallin from unproven European to the top of the sport. But Wallin will take quite a steep leap in competition by challenging the 6-feet-9, 260-pound Fury.

To date, the 28-year-old Wallin’s most noteworthy win was a 12-round, unanimous-decision defeat of domestic rival Adrian Granat (15-2, 14 KOs) in April 2018 in Sundsvall, Sweden, Wallin’s hometown. Rust could affect Wallin as well, as he has boxed less than one round in the 16 months since his win against Granat.

Wallin’s last fight, scheduled for July 12 in Tacoma, Washington, was canceled that morning because the Washington State Department of Licensing wouldn’t allow his 40-year-old opponent, BJ Flores, to fight due to an undisclosed medical issue. Wallin’s previous fight ended prematurely when Nick Kisner (21-4-1, 6 KOs, 1 NC) suffered a cut in the first round that caused their scheduled 10-rounder to result in a no-contest April 13 in Atlantic City, New Jersey.

ESPN+ will stream the entire Fury-Wallin card in the United States (7:30 p.m. ET/4:30 p.m. PT). It’ll be broadcast by BT Sport Box Office as the main event of a pay-per-view show in the United Kingdom (£19.95).

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