By Edward Chaykovsky

One of the biggest fights to be made is a unification between undefeated heavyweight champions Anthony Joshua (18-0, 18 KOs) and Deontay Wilder (37-0, 36 KOs).

Wilder is back on Saturday night in Alabama, where he defends his WBC title against Gerald Washington. Joshua returns on April 29th at Wembley, in one of the year's biggest fights, by defending the IBF title against Wladimir Klitschko. The WBA, IBO titles will also be at stake in Joshua-Klitschko.

Washington is a late replacement for Polish contender Andrzej Wawrzyk, who failed a drug test. The last minute change came with positive feedback, as most fans and experts see Washington as a better opponent than Wawrzyk.

Joshua has not been impressed with Wilder's level of opposition. To date, Wilder's most accomplished opponent has been Bermane Stiverne, who the Olympic bronze medal winner unseated in January 2015 to capture the WBC title.

In order to make their mega-clash a big success in the future, Joshua would like to see Wilder step on the gas by fighting better opponents.

And as a fan of the sport, Joshua is not moved by what he calls "easy pickings" being selected by Wilder's handlers.

"I think Wilder needs to fight better opposition," Joshua exclusively told Sky Sports. "Washington is good, but he's up and coming still. It was a last minute call-up as well. I know his last opponent failed a drugs test unfortunately, but I would love for him to postpone it for another month and get someone who could train for a world championship fight."

"Wilder has been a professional for around eight to nine years and I want to see a bit more, and there is nothing wrong with that. I'm speaking from a fan's perspective, because I get it. After three years as a professional, they want more, so after nine years as a fan I'm saying: 'Wilder we want more from you', and there is nothing wrong with that."

"Good luck against Washington, but I think the other contenders in the heavyweight division need challenging as well, so I think it would be good for Wilder to force these type of fights, rather than taking easy pickings."