Barcelona defender Jean-Clair Todibo has confirmed he has tested positive for Covid-19.
Barcelona said on Wednesday an unnamed squad member had tested positive.
Frenchman Todibo, 20, was one of nine reporting for pre-season training, showed no symptoms and has been quarantined at his home.
Also on Wednesday fellow La Liga side Athletic Bilbao said six players had tested positive as they returned for pre-season training.
Valencia confirmed two cases of Covid-19 this week, while Atletico Madrid reported two positive tests before their Champions League quarter-final.
Barcelona said Todibo had not been in contact with any senior players, who travelled to Lisbon on Thursday to prepare for their Champions League quarter-final against Bayern Munich on Friday.
"I am at home following the proper health protocol," said Todibo on Twitter.
"I really want to go back to training, but now it's time to stay home until the virus is over."
Because of the coronavirus pandemic, the Champions League is concluding with a 'final eight' tournament in Lisbon, comprising single-leg games held behind closed doors.
Everyone who has been in contact with Todibo has been tracked to perform tests.