Robinho has been tipped to join former team-mate Kaka at expansion club Orlando City ahead of their debut season in the MLS next year but the his future remains unclear amid interest from a number of teams.
The Brazilian forward has attracted interest from South America, with duo Cruzeiro and Atletico reportedly tabling bids for the 30-year-old's services.
Former club Santos, where Robinho emerged from to win two league titles before joining La Liga giants Real Madrid in 2005, are also among the list of suitors.
However, Rodrigues told Globoesporte finances were proving to be a stumbling block.
"Robinho has a strong connection with the city. Here he is an idol, we all want to see him with our mesh," he said.
"There was contact with his lawyer, but the negotiation is difficult. Robinho wants Santos, however, it is difficult for us to meet his financial demands.
"It's a difficult negotiation, but not impossible."