Busquets, 32, captained Spain in Friday’s friendly draw with Portugal in Madrid. Spain’s players did not train on Sunday but underwent tests, which revealed Busquets’ positive result.
The Barcelona midfielder left the national team on Sunday in medical transport as per the protocol while other players, who have yet to be vaccinated, will remain in isolation and have personalised training.
All media activity has been cancelled while Tuesday’s international friendly against Lithuania in Madrid will be played by the Spain Under-21 team, whose manager is Luis De la Fuente.
Aside from Busquets, eight players — Jose Gaya, Mikel Oyarzabal, Thiago, Adama Traore, Aymeric Laporte, Eric Garcia, Fabian Ruiz and Ferran Torres — in Spain’s squad have tested positive for COVID-19 since the start of the pandemic.
UEFA allows for a change of a player from the registered list due to injury or COVID-19 but does not allow for the increase in the number of players called up, which is 24.