The Argentine forward has attracted the interest of some of Europe's biggest clubs with his fine performances in 2014-15 and both Juve and United are keeping a close eye on the 21-year-old's situation.
However, Zamparini, who revealed that his relationship with the player has completely broken down, would prefer it if Dybala were to stay in Serie A, although he has stressed that money will eventually be the decisive factor, citing Javier Pastore's move to Paris Saint-Germain as an example.
"There has not been any contact with Napoli but it is true that Marotta has been in touch for Juventus," he told Tuttosport.
"He told me that Juventus will be right there if we decide to sell Dybala. They are very much interested in signing him and are ready to open talks.
"I told him that I would be more than happy to sell Paulo to Juventus if possible. I would actually prefer for him to stay in Italy.
"I know Marotta, though, so I immediately made it clear that I will not give him a discount. We all know what happened with Pastore."
Dybala, who has scored 11 goals in 21 league games for the Sicilians so far this season, has a contract with Palermo until June 2016.