Juventus have announced midfielder Rodrigo Bentancur has tested positive for COVID-19.
The Uruguay international – who played the entire match as Juve defeated Spezia 3-0 in Serie A action on Tuesday – is asymptomatic, as confirmed by the club on Thursday.
Bentancur is now isolating and seemingly certain to miss Saturday's league game against Lazio in Turin.
"The club is in contact with the relevant health authorities for the definition of an effective implementation of the protocols required to allow the training and competition activities of the team group," Juventus said in a statement.
The 23-year-old's positive test also makes him a major doubt for the upcoming return leg of the last-16 Champions League tie against Porto.
Juve lost 2-1 in the first meeting, with the reverse fixture to take place next Tuesday.
Bentancur has made 33 appearances in all competitions this season, including 18 starts in the league for Andrea Pirlo's side.