Benn and Eubank will battle it out on October 8 at London’s iconic O2 Arena, almost 30 years after their dads’ famous rematch.
Due to the difference in size between the two fighters, a catchweight is believed to have been agreed at 157lb, meaning Benn will have to put on a few pounds from his usual 147lb weight class.
Eubank meanwhile has spent most of his career competing at middleweight at 160lb, though he has previously campaigned as high as super-middleweight at 168lb.
If he wins, he could target a world title shot against the likes of Canelo, Charlo and Golovkin.
However, Hearn doesn’t think he would stand much of a chance as he believes they are levels above him at the moment.
But that doesn’t mean to say that he thinks that he isn’t a good boxer – far from it in fact.
Speaking on The DAZN Boxing Show, when asked to assess Eubank’s resume, Hearn said: “If you’re looking at wins, Chris Eubank Jr beat a faded James DeGale.
“But he still beat a James DeGale. He had a good fight with George Groves. I know that George was injured at the end of the fight and going into that fight, but you know, I rate Eubank.
“I think he’s tough as granite. He’s got a great chin like his dad.
“But I don’t see him necessarily as an elite middleweight. I think he’s a world class middleweight, but I don’t believe he beats any of the good [fighters], the world champions at middleweight. I don’t think he beats Charlo, Golovkin, of course, Canelo, of course, but listen, it’s a massive fight for him.
“You talk about Conor Benn winning this fight, if Eubank wins this fight, I think he can fight a Gennady Golovkin in the UK or a Canelo Alvarez at Wembley. So it’s a massive fight for both [fighters].”
Eubank heads into his all-British clash with Benn as the big favourite with the bookies.
However he enters the bout coming off the back of arguably the best performance of his career to date against the dangerous Liam Williams.
Benn, meanwhile, has yet to taste defeat from his 21 fights, with 14 of his victories coming by way of knockout.