The French club's goalkeeper has claimed that the Colombia international is certain to move to the Stade Louis II unless the Blancos make a late bid for the striker
The newly-crowned Ligue 2 champions are willing to meet the Colombia international's €60 million buyout clause, as well as offer the in-demand forward a net salary of €10m per season.
Atletico and Falcao have thus far refused to comment on the mounting speculation, but Subasic has been informed by Monaco that the deal is all but done.
"I will tell you what I have heard, and that is that Falcao is 90% coming to Monaco," the Croatia international told Sportske Novosti.
"For sure, it is what they have told us, with only a small possibility that Monaco could only lose him if Real Madrid were to come in, but that is now unlikely.
"If he does not leave for the Bernabeu, he will come to Monaco."
Falcao, 27, has scored 69 goals in 87 games in all competitions since arriving at the Vicente Calderon from Porto two years ago.