Sources have told ESPN that United boss Erik ten Hag believes he cannot work with Ronaldo again after the striker said he "doesn't respect" the Dutch manager.
Australian Professional Leagues CEO Townsend said he had contacted Ronaldo's agent Jorge Mendes with an audacious bid to lure him to Australia, where his grandparents live.
"We haven't been in Nani's ear but we've certainly registered our interest in bringing [Ronaldo] to Australia," Townsend told SportFM.
"It's obviously a long shot but we certainly have a proposition here in Australia for him to consider.
"We're in dialogue and we'll see where that goes."
Sources have also told ESPN that the majority of the United squad do not believe there is a way back for Ronaldo.
The Portugal international is preparing for his fifth World Cup this month, although he will not play in the final warm-up game due to a stomach bug.
Ronaldo made a number of revelations in the TV interview, the first part of which aired on Wednesday, including criticism of young players in modern football.