Serie A side Genoa have announced 14 people at the club have returned positive tests for coronavirus.
The cases, from among the playing squad and other staff, were confirmed following the 6-0 league defeat to Napoli on Sunday.
"The club has activated all the procedures as per the protocol and informed the authorities. The club will give updates as the situation evolves," Genoa said in a statement on Monday.
This news means Saturday's scheduled game against Torino could now be in doubt.
It also means Napoli will likely need to carry out tests of their squad before Sunday's clash with champions Juventus.
Sampdoria also confirmed on Monday that forward Keita Balde had tested positive for COVID-19 and will now follow the necessary health protocols.
The player is due to join Sampdoria from Monaco this week on loan.