The 42-year-old has spent the last two years working, predominantly, in his native Mexico after ending a decade-long association with WWE in 2015.
But Mysterio could leave Lucha Underground after the conclusion of its third season later this year, and will be free to sign with another wrestling promotion at the expiry of a standard 90-day non-compete clause.
Whilst the smart money would normally be on a return to wrestling's biggest stage, the former World Heavyweight Champion has previously spoken of his preference for a less demanding schedule.
And GFW, a company looking to expand its talent pool after a recent re-brand, could steal a march on their rivals by offering him a short-term deal.
Vince McMahon and WWE, meanwhile, are said to be desperate to bring their former star back, having failed to cultivate any comparable Latin stars in the time since his departure.
Barrasso, however, also claims that Mysterio could yet be persuaded to sign on for another season with Lucha Underground.