Atletico Madrid Los Colchoneros is looking for a solution

EFE
Atletico Madrid Champions League in the round of 16 of the first leg matches against Chelsea will not be played in the Spanish capital.
This is due to the Spanish government’s extension of restrictions on entry flights from the United Kingdom, as well as from South Africa and Brazil, which prevents the Blues from making such a trip.
Travelers from the three countries mentioned above are denied access to Spain without a ten-day quarantine if they are not citizens or residents of Spain or Andorra due to the apparent coronavirus variants that have been detected.
As a result, Los Colchoneros are looking for alternative places, Bucharest being the most likely city to host the game.
Countries such as Belgium, France, Portugal and Germany are excluded, as they have imposed the same measures as Spain.