Falcao has long been linked with a big-money move away from Atletico and reports in Spain over the weekend suggested Monaco were closing in on the prolific Colombia international.
According to those reports, Falcao was set to have a medical with the French outfit on Monday ahead of a £50million move.
Simeone assured after Sunday's home match with Real Mallorca that "there is still nothing official" on whether Falcao will be at Atletico next season or not, but also reiterated: "Whatever happens to Falcao I will be happy.
"I've known him since we were at River Plate. That was for a year, and now a year and half at Atletico. He has helped us win titles.
"If he has to leave, I thank Falcao for all that he's given us."
Atletico defender Juanfran Torres, meanwhile, believes the 27-year-old Falcao will end up staying at the Vicente Calderon.
He said in Marca: "People are always saying the same things about this matter, but we, honestly, think that he's going to stay.
"He's a player who has a contract, who is happy at Atleti, who has won titles, and who hasn't said goodbye to us. He hasn't given us any sort of farewell talk.
"I think he's going to stay. Hopefully he stays."