Twelve people, including players and staff from the Venezuelan national football team, tested positive for COVID-19, officials said on Saturday. This comes a day before they play the opening match of the Copa America against hosts Brazil.

Tournament organisers were informed about the cases shortly after the Venezuelan team arrived for the competition.

“The health department was notified by CONMEBOL (the South American football confederation) that 12 members of the Venezuelan national team‘s delegation, including players and coaching staff, tested positive for COVID-19,” a statement read.

“All are asymptomatic and isolated in individual hotel rooms. They are being monitored by CONMEBOL’s team and health department officials,” the statement added.

The department did not say how many players tested positive.

CONMEBOL said Friday it would allow teams unlimited substitutions for players who are ruled out because of positive COVID-19 results or contact with positive teammates, meaning the cases were unlikely to force the cancellation of any matches.

He said health officials were tracing everyone the infected people had contact with and would carry out genetic testing on their test samples to determine which strain of the coronavirus they were carrying.

Venezuela are slated to face Brazil Sunday in Brasilia’s Mane Garrincha stadium to open the Copa America, which was already delayed by 12 months because of the pandemic.

The tournament nearly had to be called off again when original co-hosts Argentina and Colombia fell through over a surge of COVID-19 in the former and violent anti-government protests in the latter.