The Brazilian goalkeeper has been linked with a move away from Loftus Road since QPR suffered relegation at the end of last season, and a number of clubs have been linked with a summer swoop.
Arsenal had been credited with an interest after Cesar admitted he would like to stay in London, but in recent times it has been reported that Fiorentina were leading the chase.
However, Prade has been quoted as telling Sky Sport Italia that Fiorentina have not even made an enquiry about Cesar.
"I have never contacted either QPR or the agent of the Brazilian goalkeeper," he said.
Other reports in Italy suggest that talks have taken place, with Cesar's agent quoted as telling Radio Blu that a deal will be difficult if Fiorentina are unwilling to meet his wage demands.
It is also rumoured that Cesar would be prepared to wait until January for a move as he is not worried about losing his place in the Brazil side ahead of the World Cup.