Napoli's problems continued when they were held to a 0-0 at home by Genoa in a tense atmosphere and jeered off the field on Saturday following a tumultuous week at the Serie A club.
The San Paolo stadium was barely one third full on a damp evening after a week in which the team defied orders from club owner Aurelio De Laurentiis confining them to a training retreat.
Players were greeted with insults as they warmed up on the pitch and there was near silence when the stadium announcer read out the Napoli line-up before the game.
Lorenzo Insigne thought he had put Napoli ahead after two minutes but Hirving Lozano was ruled offside in the build-up. After that, it was a lacklustre display from Napoli which further angered their supporters.
Napoli, runners-up in three of the last four seasons, stayed seventh on 19 points, 12 behind leaders Inter Milan.