Hearn was gutted to see Ortiz turn down two offers to replace Jarrell Miller for the bout at Madison Square Garden.
Miller tested positive for three banned substances so had to be pulled from the card.
Ortiz, whose only career defeat came against WBC heavyweight champion Deontay Wilder, was top of the shortlist.
However, the Cuban claims he was offered a “low ball” sum of £3.8million ($5million) – much below his £7.75m ($10million) demand.
But Hearn claims he could still re-open negotiations with Ortiz.
“There’s a couple of other guys in the mix,” Hearn said after explaining he is in deep talks with Michael Hunter and Andy Ruiz Jnr.
“We mentioned them in the past. Even Luis Ortiz could come and say, ‘Let’s go,’ and we’d do that.
“The difference is Luis Ortiz is a different draw than Andy Ruiz.
“Ruiz has a different value, so the pay-per-view numbers would be less for Andy Ruiz than they would for Luis Ortiz [in the UK].
“The gate would probably be less for Andy Ruiz than it would for Luis Ortiz.
“Obviously, he doesn’t have the same value.”
Hearn also explained why he is working on deals with Hunter and Ruiz.
“We represent Michael Hunter, so that fight is a lot easier to do,” he added.
“Al [Haymon] represents Ruiz. If he wants to give him the opportunity, it’s there as well. Star-wise, the Ruiz fight is more interesting in my opinion.
“Hunter is a tricky fighter. He’s a very clever fighter. He’s got one defeat on his record to [Oleksandr] Usyk.
“So you can compare Joshua to Usyk. Andy Ruiz has a decent Mexican following. It would have a good Hispanic interest.”