The striker is the top scorer in Serie A this season, having scored 22 league goals for Torino, who co-own the player together with Juventus.
Immobile's form has earned him a place in Cesare Prandelli's provisional Italy squad for the FIFA World Cup in Brazil.
The 24-year-old is not expecting to represent Juve later in his career but is open to a move to Naples, having grown up in the city.
"An eventual return to Juventus after the experience with Torino? I do not think that will happen," Immobile told Italia 1.
"Would I like to wear the Napoli shirt in the future? Certainly, they are the team of my city."
Immobile will battle it out with Mario Balotelli, Antonio Cassano, Alessio Cerci, Mattia Destro and Giuseppe Rossi to be one of Prandelli's striking options at the finals.
