Genoa says another 12 members of the match squad have the coronavirus, taking the total number of cases at the Serie A club to 14.
It was revealed over the weekend that goalkeeper Mattia Perin and midfielder Lasse Schne contracted the virus.
Further tests showed it had spread through the matchday squad, and Genoa said the number of members positive for COVID-19 has increased to 14 between team members and staff.
Genoas Serie A match against Torino on Saturday is now a doubt.
Genoa lost at Napoli 6-0 on Sunday. Napoli players and staff will undergo further tests before their match against Juventus.