The Spanish club issued a short statement announcing that the 48-year-old had the virus, but gave no further information about his condition or any implications for the playing squad.
Zidane is under pressure for Real’s poor results and performances, including Wednesday’s Copa del Rey defeat by third division Alcoyano.
Real, second to city rivals Atletico in La Liga, face Alaves on Saturday.
Despite a run of cup defeats – the loss at Alcoyano coming a week after they were knocked out of the Super Cup by Athletic Bilbao – the Spanish champions will be looking to extend an eight-game unbeaten run in the league when they host strugglers Alaves.
Real are second in the table after 18 games, seven points adrift of Atletico, who also have a game in hand.
