The heavyweight champions have already verbally agreed to a two-fight deal in 2021.But the undisputed title decider faces uncertainty with AJ first needing to beat Kubrat Pulev, 39, and Fury facing Wilder, 34, for a third time.
The rivals then need to agree financial terms and logistics for the most lucrative fight in British boxing history.
Heavyweight legend Tyson - preparing to box for the first time since 2005 - wants Joshua, 30, and Fury, 32, to put their differences aside and finally share the ring.
He said: "They're all exciting fighters, they're all going to make a great deal of money but they just need to fight each other.
"Stop bull****ing and just fight each other.
"Fight each other a couple of times and when that stuff is over you guys can say, 'Hey, listen, we did it out way'."
Tyson announced plans to make a comeback earlier this year and WBC champion Fury was even approached to face his namesake in an exhibition.
But Iron Mike will instead box 51-year-old Roy Jones Jr in an eight-round pay-per-view spectacle.