Anthony Joshua's promoter Eddie Hearn is eager to see if Joseph Parker is the "real deal" when the rising Kiwi heavyweight takes on Carlos Takam.

Parker and Takam square off in south Auckland on Saturday night in an IBF eliminator.

The winner gets the mandatory right to challenge Joshua for his world title.

The fight is being screened live in Britain and Hearn said he and Joshua would be watching with interest as a key part of their future gets mapped out for them.

"It's a great fight ... Joseph Parker is well renowned now around the world in people in boxing. There are a lot of people talking about him," Hearn told Sky Sports UK.

"But Takam is a serious fight. It is going to tell us a lot about Parker. He has beaten a lot of older aged guys who probably Josh faced in the early part of his career as well. Now this is the real test and we are going to find out if Parker is the real deal.

"If he beats Takam, then yes, I believe he is the real deal."

Hearn said this fight against a world class opponent was the true barometer of Parker's progress and potential.

"It's difficult because you need that step up. For Josh the step up was Kevin Johnson, then it was Dillian Whyte, then it was Charles Martin," Hearn said.

"So some fighters who have the ability just keep on stepping up. But some get to a stage, and it could be Parker against Takam, where they face those guys and they can't overcome that level.

"I'm not sure (about Parker). He's exciting, he's dangerous, he's fast, he can really punch ... but when you have someone of Takam's resolve ... like I said, it's going to tell us all we need to know."

Hearn admitted former world champion David Haye warned him off pitting Joshua against Takam because of the Paris-based Cameroon fighter's experience and dangers.

If Parker won, Hearn suggested he would be willing to put the New Zealander on a Joshua undercard later in the year to build his profile and hype up a looming title fight.

"I think his people know that we are further down the line than them. But these are still two young guys improving. So although they may say they want to fight ASAP, I think they are happy to let it build as well."