Azpilicueta, who moved to Chelsea from Marseille in August 2012 for £6.5million, has played just seven games under Jose Mourinho this season.
The Spain international's best period at Chelsea came under fellow countryman Benitez.
Azpilicueta has since lost his place in Chelsea's starting line-up as Mourinho has instead opted to play Branislav Ivanovic at right-back.
Napoli manager Benitez is said to be lining up a January bid for the 24-year-old in hope that he can convince his former side into selling the full-back.
Chelsea outcast Azpilicueta would surely jump at the chance of working under Benitez again, especially as it could boost his hopes of worming his way into Spain's 2014 World Cup squad.
Benitez has got off to a fantastic start at Napoli, with his side winning nine of their first 11 Serie A games.