Hearn told Sky Sports News it is the only way to find out if the WBC titleholder Wilder is serious about fighting Joshua even though reports out of the United States on Monday suggested he had accepted a two fight deal with the 2012 Olympic champion and now holder of the WBA, WBO and IBF belts.
Complicating matters is that Joshua is already due to take on WBA mandatory challenger Alexander Povetkin.
“We’ve got to get to the bottom of it today, but one thing I can tell you is that by the end of this week Deontay Wilder will have a contract in front of him and we’ll see if he’s real,” said Hearn.
“I think Wembley is where Anthony Joshua wants it to take place. He had a brilliant night there against Wladimir Klitschko and it seems a natural home.”
If the fight is confirmed, it will be the biggest bout seen in the division in years.