Deontay Wilder then potentially awaits Joshua should he pass his latest test, but Hearn is in no rush for the 28-year-old to fight abroad just yet.
"As a heavyweight world champion and a major star in world boxing, [Joshua] should box over here at some stage," he told Sky Sports News. "There's always been that myth really that in boxing you have to crack America, but I don't see why.
"Look at what we are doing in the UK, look at the spectacles we are creating, [Joshua] is very happy boxing in the UK. I just think it's a natural progression to fight in other countries and he wants to break down boundaries as well and part of that should be boxing in America, Africa, the Middle and Far East, but right now he is very comfortable doing what he's doing.
"I am not sure if the US is imminent but I would expect him to box in America in the next 12 months."