"Livorno wishes to communicate that Davide Nicola has been relieved of his duties as coach," the club said in a statement.
"The club offers its most sincere thanks for the commitment, professionalism and dedication he has always shown."
"The team is flat, it's got no fight and when it concedes a goal it shows no reaction so we needed a change," Spinelli said.
"Perotti knows our setup and the players very well and he has already saved us from relegation before."
Nicola, 40, led the club to promotion last season but his team have taken just one point from their last eight matches.
It was widely speculated in Italian media that Nicola would be dismissed following Saturday's 3-0 home defeat by Parma.
The Tuscan side have 13 points from 19 matches, the same haul as bottom club Catania.
- Sports & Recreation
- Davide Nicola