There have been reports of Ralf extending his contract in recent weeks.
"There was no renewal. He still has an agreement until 2014," agent Andrea Costa told Radio Blu.
"He would be happy to come to Europe, but the intentions of the Brazilian club are clear and the situation has become difficult. The Viola might have to wait until January.
"Fiorentina are making an enormous effort, but this is a very difficult negotiation process."