Uefa says the Champions League quarter-final between Atletico Madrid and RB Leipzig is "planned to be played as scheduled" on Thursday despite two positive tests for coronavirus at the Spanish club.
Atletico said all members of the travelling party to Portugal for Thursday's one-off match against the Germans underwent tests on Saturday and that two had returned positive results for Covid-19 on Sunday.
Those two players were revealed by Atletico to be Argentine forward Angel Correra and Croatian defender Sime Vrsaljko.
"First team players and coaching staff underwent new PCR tests on Sunday and all results have come back negative," Atletico said in a statement. "After two first team members tested positive on Saturday and following the health protocol, further exams were carried out on their relatives, all of which were negative.
"The first team [returned] to training on Monday evening without Angel Correa, who is asymptomatic and self-isolating at home, and Sime Vrsaljko, who was recovering from an injury and not training with the group.
"The Croat is also asymptomatic and will remain at home by decision of the medical services, although his case is considered to be resolved by the health authorities, having generated antibodies several months ago."
Atletico said Uefa, as well as the Spanish and Portuguese football and health authorities, have been informed and that a fresh round of tests will be carried out on the squad and support team.
They admitted this could mean last-minute changes to travel schedules as well as accommodation plans 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," added the statement.
"We also request the utmost respect over the identity of the two positive cases."
However, Uefa are expecting the match between Atletico and Leipzig to go ahead, with a Uefa spokesman saying: "The match is planned to be played as scheduled. We have no further comments to make."
The team were due to travel to Portugal on Monday for the closing stages of the Champions League which is being held in Lisbon as a precaution against Covid-19 rather than risk having teams travelling across Europe for home-and-away ties.
The self-contained eight-team tournament will be staged behind closed doors, starting on Wednesday with the final set for Lisbon on August 23.
Spain has so far been one of the countries worst affected by the coronavirus pandemic, with 310,000 registered infections and 28,500 deaths.
Although most sports have returned from a months-long lockdown caused by the virus, there are concerns that numbers of cases are beginning to rise again.
In recent days, Spain has seen local quarantines imposed in the Basque Country, Catalonia and Aragon.
Protective face masks have been made compulsory in several busy areas, especially in the Madrid region.
Last month, Atletico's city rivals Real Madrid announced forward Mariano Diaz had tested positive for Covid-19.
Sevilla, meanwhile, reported an unnamed player had also contracted the illness.
Real have since been knocked out of the Champions League but Sevilla are still involved in the Europa League. They play English side Wolves in their quarter-final in Duisburg, Germany, on Tuesday.
The Champions League had been put on hold since March because of the virus with the last-16 stage only completed on Friday and Saturday.
For its 'Final Eight' tournament in Portugal, Uefa has planned strict protocols - each team will have to provide test results before travelling to the country, and will be tested again on the eve of their first match.
Each positive test will require the individual to self-isolate.
