His agent has confirmed that Napoli do not have an option to sign him outright at the end of the season.
"The reports about Napoli not taking up their option on him surprise me," Cardoso da Silva told Radio Renascenca. "Primarily because one does not exist.
"Rolando is in Naples on a simple loan deal from Porto.
"If clubs are interested in signing him at the end of the season then they are free to do so as Napoli have no preferential right.
"A return to Porto? I can't rule that out."