Valencia have criticised Atalanta coach Gian Piero Gasperini for taking charge of his side's Champions League match against the Spanish side in March despite suffering from symptoms of the novel coronavirus.
Gasperini told Italian newspaper La Gazzetta dello Sport on Sunday that he felt ill on the day before the last-16 second leg match in Valencia on 10 March, which was played without spectators as northern Italy was then the epicentre of the virus in Europe.
He also confirmed he has since tested positive from an antibodies test.
Valencia later issued a statement saying they were surprised at Gasperini's admission he had symptoms with the coronavirus before the match and did not take preventative measures.
"Such actions, if this was the case, would have put at risk numerous people during the trip to - and stay in - Valencia," added the statement.
"It should be remembered tat this game was held behind closed doors amidst strict safety measures... to prevent the risk of COVID-19 contagion, precisely due to the presence of persons from an area already publicly classified as 'at risk'."
A week after the match, which Atalanta won 4-3 for an 8-4 aggregate victory, Valencia announced that 35% of their squad and staff had tested positive for the virus.
Gasperini detailed his suffering in the interview with Gazzetta, saying: "I was scared. The day before the game I was sick, and the afternoon of the game I felt worse. I slept badly the next two nights.
"If you look at the pictures, I did not look good on the bench. I didn't have a fever, but I felt like I did."
Gasperini added that he self-isolated for three weeks at Atalanta's training ground after the trip to Valencia and while soccer leagues around the world were postponed due to the pandemic and respected social distancing with his family.
The first leg between the two sides at the San Siro in Milan, attended by more than 40,000 fans, is believed to have led to many infections in Italy and Spain, with Bergamo mayor Giorgio Gori later describing the match as a "biological bomb".
Italy has the third highest coronavirus death toll in the world, with over 33,000 deaths, while over 27,000 lives have been lost in Spain due to the virus.