Wilder remained on course for a high-profile bout with the undefeated Briton by beating Bermane Stiverne with a first-round knockout in New York overnight.
'The Bronze Bomber' immediately targeted Joshua, who has previously spoken of his desire for a unification match at some point in 2018.
Asked about the prospect of a fight still being on the cards, Hearn told Sky Sports News: "I think 2018, we want to see Deontay Wilder against Anthony Joshua, no question.
"I was really interested to see the weight of Deontay Wilder on the scales, 15st 9. I texted that to Anthony today, Deontay Wilder, 15st 9. I shouldn't really tell you the reply, but it was 'I'll eat him,' and the size difference is huge. It's two-and-a-half stone now between those two."