The former AC Milan and Barcelona star is unlikely to return to Europe in 2012 following reports he could be heading for Greece, with his representative denying the rumours
De Assis' message comes just hours after Flamengo said they were unaware of such interest after a spokesman for potential new Panathinaikos owner Sultan bin Abdul-Aziz Al Saud revealed the former Barcelona star will be in Greece by the end of the year to sign with the Athens giants.
However, Ronaldinho's agent has said the Panathinaikos talk is nothing more than a transfer market rumour.
"We have many friends in Greece and all I can say that the rumours that are circulating now are all false," De Assis told Lancenet.
"Ronaldinho is happy at Flamengo and he does not want to leave."
Ronaldinho joined Flamengo in January from Italian giants AC Milan and his deal there expires in 2014.