Valencia have confirmed "around 35 per cent" of their players and backroom staff have tested positive for coronavirus.
The LaLiga club played the second leg of their Champions League tie against Italian side Atalanta last Tuesday having lost the first leg in Milan on February 19.
A statement on Valencia's official website said: "Several further tests for the Covid-19 coronavirus amongst Valencia CF coaching staff and players have come back positive.
"All cases are asymptomatic and those involved are currently isolated at home, receiving medical assessment and carrying out their scheduled training plan.
"Despite the strict measures adopted by the club after their UEFA Champions League game against Atalanta on February 19 in Milan – an area confirmed as 'high risk' by the Italian authorities days afterwards – which included maintaining a distance between the squad and club employees/the general public, these latest results show that the exposure inherent to such matches has caused a positive test rate of around 35 per cent."
Valencia, seventh in LaLiga, lost their last-16 Champions League tie to Atalanta 8-4 on aggregate.
Atalanta, based in Bergamo, staged the first leg 55 kilometres away at the San Siro in Milan because their Gewiss Stadium does not meet UEFA requirements.
The Spanish FA suspended LaLiga on March 12 after a Real Madrid basketball player, who shares training facilities with the club's footballers, tested positive for the virus.
