It kicks off at the Stadio Franchi at 17.00 UK time (16.00 GMT).
The Partenopei have a 100 per cent record after six Serie A rounds, but suffered their first defeat of the season in a 3-2 Europa League loss to Spartak Moscow on Thursday evening.
Mario Rui was sent off in the opening half-hour of that match, which inevitably changed the course of the encounter, but it was still a knock to their confidence.
Fiorentina have put in some wonderful performances under new coach Vincenzo Italiano, but not always getting the results they deserved.
Gaetano Castrovilli is still out after bruising his ribs in a collision with the upright.
The good news is that Gonzalez returns from suspension to join Vlahovic and ex-Napoli star Callejon in the trident attack.
It’s a duel between 4-3-3 formations and Alvaro Odriozola gets the nod ahead of Lorenzo Venuti.
Fiorentina: Dragowski; Odriozola, Milenkovic, Martinez-Quarta, Biraghi; Bonaventura, Pulgar, Duncan; Callejon, Vlahovic, Gonzalez
Napoli: Ospina; Di Lorenzo, Rrahmani, Koulibaly, Mario Rui; Fabian Ruiz, Anguissa, Zielinski; Lozano, Osimhen, Insigne