Lazio coach Stefano Pioli has ordered his team into a training camp after Sunday night's 5-0 defeat to Napoli.
Gonzalo Higuain scored twice as Napoli ran riot against Lazio at Stadio San Paolo on Sunday, consigning Pioli's side to their second defeat of the season.
Upon returning to their Formello training ground at around 03.00 local time on Monday, Pioli made his players spend the night in the complex rather than be allowed to go home.
They will remain there until after Wednesday night's home game against Genoa.
"We're not satisfied with our performance and we have got to ask ourselves why we cannot find any consistency," Pioli said at his postgame news conference. "We've got to look each other in the eyes.
"The important thing now is that we demonstrate that we're different to this; that we want to and can be an ambitious side. I don't think we need many words.
"I continue to believe strongly that I have a competitive, responsible group of professionals who will know they have to roll up their sleeves because we cannot perform like we did tonight."
Lazio are 10th in Serie A having won their two home games, but have lost both of their away games this season.
Pioli's men have conceded nine league goals on their travels, while a late Dnipro Dnipropetrovsk equaliser denied them victory in their opening Europa League game on Thursday.
The Biancocelesti face St Etienne in Europe next week at the Stadio Olimpico by which time they will hope to have picked up two more Serie A victories, including a potential first away win at Hellas Verona on Sunday.
Lazio faced criticism after a number of supporters were waiting for the team when they arrived back in the city in the early hours of Monday morning, with La Gazzetta dello Sport reporting that the words "11 unworthy" were painted on the walls outside the training ground.