By Keith Idec

NEW YORK – Doubters question whether Sergey Kovalev has been properly prepared in his first 26 professional fights for the challenge he’ll encounter Saturday night at Boardwalk Hall in Atlantic City.

Kovalev even admits we’ll have to wait until after he boxes Bernard Hopkins to truly know. One thing is clear, though. Kovalev (25-0-1, 23 KOs) genuinely appreciates what is by far the most important opportunity of his five-year pro career – a light heavyweight championship unification fight against the legendary Hopkins (55-6-2, 32 KOs, 2 NC).

The WBO light heavyweight champion will make more than $1 milllion for fighting Hopkins, the IBF and WBA champion, in an HBO “World Championship Boxing” main event (10:45 p.m. ET). Just two years and five months ago, Kovalev was paid $5,000 for his rematch against Darnell Boone. Kovalev beat Boone by second-round technical knockout and impressed Main Events chief executive officer Kathy Duva enough in what amounted to a tryout that she signed him to a promotional contract.

Kovalev revealed before an open workout Tuesday at Gleason’s Gym in Brooklyn that the $5,000 he earned for beating Boone (19-21-4, 8 KOs) in June 2012 marked the first time he was paid an actual purse as a professional boxer.

“I don’t know if everybody knows, but I fought for three years for free, looking for any promoter,” Kovalev, 31, said. “Nobody wanted to sign me. But in [2012], Kathy Duva, Main Events, signed me and my career has been going up, better. I waited a long time for fights like that, on TV, because it’s a very good opportunity to show good boxing for boxing fans, to create history for myself, my family, my son.”

Russia’s Kovalev wouldn’t have had a chance to impress Duva without manager Egis Klimas, who bankrolled the first three years of Kovalev’s career. Working without a promoter or TV exposure limited how much Klimas could pay Kovalev, which was why he wasn’t paid actual purses for the first three years of his pro career.

“My manager, Egis Klimas, paid for my opponents, for my food, for my rent, hotels, my tickets – for everything,” Kovalev said. “He invested a lot of money into those three years. I did 18 fights for free. I got my first purse money for my 19th fight, my rematch with Darnell Boone.”

Keith Idec covers boxing for The Record and Herald News, of Woodland Park, N.J., and BoxingScene.com. He can be reached on Twitter @Idecboxing.