One Barcelona player has tested positive for coronavirus but the club say he has not been in contact with any of the squad due to compete in the Champions League.
Barca carried out COVID-19 tests on nine players on Tuesday - Pedri, Trincao, Matheus Fernandes, Jean-Clair Todibo, Moussa Wague, Carles Alena, Rafinha, Juan Miranda and Oriol Busquets - who are due to return for pre-season training on Wednesday.
A statement from Barca read: "Following PCR tests conducted this Tuesday afternoon on the group of nine players due to begin the pre-season today, one of them has tested positive for COVID-19.
"The player has no symptoms, is in good health and has been quarantined at his home.
"The club has reported the matter to the relevant sporting and health authorities.
"All persons who have been in contact with the player have been tracked to perform the corresponding PCR tests.
"The player has not been in contact with any of the senior team players who are scheduled to travel to Lisbon this Thursday to compete in the Champions League."
Barca are due to face German champions Bayern Munich in the last eight of the competition on Friday night as part of the mini-tournament in Portugal.
Meanwhile, Atletico Madrid will be without Angel Correa and Sime Vrsaljko for their last-eight clash against RB Leipzig on Thursday.
Correa and Vrsaljko both tested positive for the virus but are asymptomatic and are self-isolating at home.
The other members of the Atletico squad were tested again on Sunday and have since returned negative results.
The quarter-finals get underway on Wednesday night with PSG taking on Atalanta.