Earlier reports had suggested Zenit offered Sarri £3.5m a season to come to Russian Federation following the departure of Roberto Mancini. The Pozzo family own both Watford and Udinese, and there is a chance Sarri was quizzed over whether he would be interested in taking the Watford job.
Sarri became the front-runner for the Stamford Bridge job after former Barcelona boss Luis Enrique's wage demands priced him out of the equation.
TWITTER EN_SSCNAPOLI ADELAURENTIISChelsea next manager Napoli announced Maurizio Sarri's departure on Twitter
Ancelotti will now be tasked with toppling Juventus as the powerhouses of Italian football, with the Old Lady having clinched a seventh successive Scudetto this term, with Napoli finishing runners-up. If he leaves, it would free up the Watford position regardless.
Zenit are prepared to pay Sarri's €8-million (US$9.4 million) release clause, in addition to a salary worth €6 million per season plus bonuses. Although he would prefer to join Chelsea or Watford, there is an outside chance Sarri could end up at Zenit. The arrival of Ancelotti is a real coup, he's a great tactician.
Meanwhile, he has won league titles in Italy, France, England and Germany.
Despite Napoli's lofty finish, De Laurentiis had aired his frustration with Sarri - linked with Chelsea despite his fellow Italian Antonio Conte remaining in charge there - over stalled contract talks.