Atletico Madrid say two individuals have tested positive for coronavirus before Thursday’s Champions League quarter-final against RB Leipzig in Lisbon.
The Spanish club said the unnamed individuals are isolating at home.
The positive cases were discovered after first-team players and club staff travelling to Lisbon were tested in Madrid on Saturday.
They will now be retested along with close contacts of the positive cases.
“This motivates changes in the training schedules, in the structure and development of the trip and the accommodation in the Portuguese capital,” Atletico said in a statement.
“The club will coordinate the new schedules with Uefa and as soon as there is a new plan it will be made public. It also calls for maximum respect for the identity of the two positive cases.”