An hour before Barcelona are set to face Bayern Munich in Lisbon, the Spanish club has announced the surprising news of the 26-year-old defender.
However, the France international defender is understood to have not travelled with the team due to a knee injury and was not in contact with any of the first-team players ahead of their tie against the German giants.
"After the PCR tests carried out on Thursday the first team player Samuel Umtiti has tested positive for Covid-19," the club revealed on their official website. "The player is asymptomatic, is in good health and is isolating at home.
"The Club has informed the relevant sporting and health authorities as well as tracing all the people who have had contact with the player so that they can undergo the corresponding PCR tests."
Umtiti has featured 18 times for the Blaugrana this season across all competitions in an injury-ravaged campaign.