Two members of Atletico Madrid 's travelling party for the Champions League quarter-finals in Lisbon have tested positive for the coronavirus, the club has confirmed.
The news comes as Diego Simeone's side prepare to face RB Leipzig in the Portuguese capital on Thursday with a place in the final four at stake, with the results of those positive tests potentially putting UEFA's condensed finale to the season in jeopardy as the European governing body look to conclude their showpiece tournament.
Both individuals, who have not been revealed to be either players or staff members, are currently in self-isolation at home.
"Yesterday, [on] Saturday 8 August, all members of the first team and the club's traveling party [set to head] to Lisbon underwent PCR tests at the Ciudad Deportiva de Majadahonda as required by UEFA protocol, [in order] to participate in the quarterfinals of the Champions League," the club confirmed in a statement.
"Among the results known today, two positives have appeared. Both individuals are isolated in their respective homes, and their results were immediately communicated to the Spanish and Portuguese health authorities, UEFA, the Royal Spanish Football Federation, the Portuguese Federation and the Higher Sports Council.
"The corresponding action protocol foreseen for these cases has been activated, which requires new PCR tests to be carried out on the first team and members of the expedition to Lisbon and the closest contacts of the positive cases.
"These tests will result in changes to training schedules, and in the structure and development of travel and accommodation in the Portuguese capital.
"The club will coordinate the new schedules with UEFA and as soon as there is a new plan, it will be made public. We request the utmost respect for the preservation of the identity of the two positive cases."
Atletico have not played since July 19, when they concluded their domestic campaign with a 1-1 draw against Real Sociedad , to secure a third-place finish in La Liga.
They were set to return to action this week on the back of their remarkable triumph over Champions League holders Liverpool back in March, when they turned the Reds over 4-2 on aggregate.