An unnamed Barcelona player has tested positive for coronavirus, the club confirmed on Wednesday.
The victim is one of the nine who had returned to start pre-season, and he has not been in contact with any of the players that are competing in the Champions League in Lisbon.
The nine players to have started pre-season are Pedri, Francisco Trincao, Matheus Fernandes, Jean-Clair Todibo, Moussa Wague, Carles Alena, Rafinha Alcantara, Juan Miranda and Oriol Busquets.
Barca say everyone who has been in contact with the Barcelona player has been tracked.
More tests and check-ups will follow on Wednesday ahead of training beginning on Thursday.