An unnamed squad member of Barcelona has reportedly tested positive for COVID-19.
Barcelona disclosed this on Wednesday.
He was one of nine reporting for pre-season training, showed no symptoms and has been quarantined at his home.
Barca say he has not been in contact with any senior players, who travel to Lisbon on Thursday to prepare for a Champions League quarter-final.
Barcelona play Bayern Munich on Friday, the day after Atletico Madrid face RB Leipzig.
Everyone who has been in contact with the Barcelona player has been tracked to perform tests. (BBC)