Joe Smith Jr. had never even heard the name Steve Geffrard before Geffrard was proposed a week ago as Callum Johnson’s replacement.

England’s Johnson (20-1, 14 KOs) contracted COVID-19 and withdrew last week from his shot at Smith’s WBO light heavyweight title on Saturday night. The largely untested Geffrard gladly accepted promoter Top Rank’s offer to step in for the hard-hitting Johnson on only eights’ notice.

This unforeseen opportunity still seems surreal to Geffrard, who was preparing to fight an Argentinean journeyman with a losing record last Saturday night in Delray Beach, Florida. Geffrard, 31, was shedding the last bit of weight while preparing to step on the scale for a non-televised, eight-round, 177-pound bout when he learned about the opportunity to replace Johnson.

Geffrard (18-2, 12 KOs) has won 18 fights in a row since he lost each of his first two professional fights in 2013. Though he has sparred with IBF/WBC light heavyweight champ Artur Beterviev (17-0, 17 KOs), former IBF/WBA/WBO champ Sergey Kovalev (34-4-1, 29 KOs) and former WBO champ Eleider Alvarez (25-2, 13 KOs), Geffrard has boxed a very low level of opposition outside of the gym.

“That’s one thing, he’s the unknown,” Smith told BoxingScene.com following a press conference Thursday in Verona, New York. “I know now that he has a lot of experience, he’s been in there with a lot of the best fighters in the world, and I’m expecting a great opponent.”

Despite that Geffrard had been training for an eight-rounder against an opponent who is 7-8 (6 KOs, 1 NC), Smith seems ready for the best version of a challenger who had approximately 150 amateur fights and won numerous national tournaments.

“He knows it’s a huge opportunity,” Smith said. “He didn’t have to take the hard road with professional fights to get this opportunity. He’s jumping ahead of some of the competition. But this is the biggest step up he’s gonna make in his life.”

The 32-year-old Smith (27-3, 21 KOs), who will make the first defense of his WBO belt, has had difficulty finding useful footage of any of Geffrard’s 20 professional fights.

“I haven’t really seen much footage,” said Smith, who is listed as a 12-1 favorite by Caesars Sportsbook. “I’ve seen very little. But, you know, from what I’ve seen, he’s a great boxer and comes to fight. [My trainers] see the same things I see because there’s not much footage on him. He’s a tall, orthodox fighter who’s got a big amateur background.”

ESPN will televise Smith-Geffrard as the main event of a show set to start at 10 p.m. ET from Turning Stone Resort Casino.

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