La Liga side Valencia have said more than a third of their playing and backroom staff have tested positive for the coronavirus but that all cases were currently asymptomatic.
The club had reported five cases of coronavirus on Sunday, with Argentina's Ezequiel Garay and France's Eliaquim Mangala both confirming they were among those who had contracted the virus.
"Several further tests for the COVID-19 coronavirus amongst Valencia coaching staff and players have come back positive," the club said in a statement.
Valencia travelled to Milan last month for a Champions League match against Atalanta, which was played in front of a packed San Siro stadium, before restrictions were placed on sports events in Italy -- the worst-hit country in Europe.
"Despite the strict measures adopted by the club after their Champions League game ... these latest results show the exposure inherent to such matches has caused a positive test rate of around 35%," Valencia added.
"All cases are asymptomatic and those involved are currently isolated at home, receiving medical assessment and carrying out their scheduled training plan."
The flu-like virus has wiped out the international sporting calendar, with the big five soccer leagues in Europe -- England, Spain, Germany, Italy and France -- as well as the Champions League and Europa League all suspended.
The coronavirus has infected almost 180,000 people and killed over 7,000 worldwide.