A statement from the club said the 26-year-old Spanish-born player was in perfect health and complying with the sanitary isolation protocol at home.
He was an unused substitute for Real’s last match – a 2-2 draw in La Liga away at Leganes on 19 July.
Madrid play at Manchester City in the second leg of their last-16 Champions League tie on Friday, 7 August.
UEFA said it is in contact with the club and monitoring both the situation and decisions of the relevant Spanish authorities.
