The La Liga giants said that the player was among a group of nine players that tested for the virus on Tuesday, adding that he has now been quarantined at his home.
The statement read in part: “The player has no symptoms, is in good health and has been quarantined at his home.
“Following PCR tests conducted this Tuesday afternoon on the group of nine players due to begin the preseason 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.
“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.”
