Ruiz, 21, is regarded among Spain's brightest defensive talents.
Planes said: "There is no official proposal. We are in the initial phase of negotiations with Napoli.
"It's possible that Napoli director of sport Riccardo Bigon is in Barcelona because he travels a lot. Fiorentina are also interested but it would make me happy if Victor stays in Barcelona because he is an important play.
"However, if a good offer were to arrive, it's clear that the club would sell. In fact Espanyol are already looking for an alternative to Ruiz."