While both players are still unnamed, they are said to be currently self-isolating at home in line with the protocol put up to combat the pandemic.
The news comes just days before Los Rojiblancos are due to take on German side Leipzig in the Champions League quarter-final.
In an official statement released by the club:
“Today, two positives appeared among the known results, which are now isolated in their respective homes and were reported immediately to the Spanish and Portuguese health authorities, UEFA, the Royal Spanish Football Federation, the Portuguese Federation and the Superior Council of Sports.
As such, a corresponding protocol planned for these circumstances has been activated, which requires new tests to be undertaken to first-team players, members of the Lisbon travelling party and those who are in close contact with the positive cases, and which will result in changes in the timings of training sessions, in the structure and development of the journey and the accommodation in the Portuguese capital.
“The club will coordinate the new timings with UEFA and as soon as a new plan will be made, it will be made public. We ask for maximum respect towards the identity of the two positive cases.”
The Champions League had been put on hold since March because of the virus with the last-16 stage only completed on Friday and Saturday.
In their statement on Sunday, Atletico were keen to reassure football authorities, explaining that they had followed a very strict protocol even after the end of La Liga season on July 19.
Weekly tests were carried out on July 26 and August 2.
For its ‘Final Eight’ tournament in Portugal, UEFA has planned strict protocols — each team will have to provide test results before travelling to the country, and will be tested again on the eve of their first match.