Gattuso said his players were unwatchable and soulless during the encounter against the visitors as they lost 2-0 at home.
Two goals from Federico Chiesa and Dusan Vlahovic gave Fiorentina all three points against Gattuso’s men at the San Paolo Stadium.
“We must apologise to the fans and the city, it was an embarrassing performance, today we were unwatchable,” Gattuso said at his post-match as quoted by NDTV Sports.
“We have hit rock bottom and we need to understand what we are going towards, we are a soulless team.”
Gattuso has now lost four out of five matches since he replaced Carlo Ancelotti last December as Napoli coach.
Gattuso added: “We have to look at each other, be together, let off steam and look for solutions. What we are doing is not enough.”
Napoli are now in 13th position on the Serie A table with 24 points from 20 games.
Gattuso’s men will now host Lazio in the Italian Cup quarter-finals on Tuesday.
