SAO PAULO (AP) — The referee for the Copa Libertadores clash Thursday between Argentina’s Racing and Uruguay’s Nacional was replaced after testing positive for COVID-19.

South American soccer body Conmebol said in a statement Wednesday that Brazilian Anderson Daronco and his assistants Fabrício Vilarinho, Bruno Arleu and Rafael Alves will remain isolated for 14 days, as Argentinian health protocols recommend.

Conmebol said all were asymptomatic when they took the tests on Sunday.

Daronco will be substituted by Chilean Cristian Garay, who was initially expected to work at another Copa Libertadores match in Argentina between local Defensa y Justicia and Ecuador's Delfín.

The Copa Libertadores restarted on Tuesday after a six-month halt due to the pandemic. Now Brazil, Peru, Colombia and Argentina are among the top 10 countries in the world in terms of confirmed cases of the disease.