AC Milan coach Stefano Pioli has tested positive for COVID-19, the Serie A leaders said in a statement on Saturday.
Milan said the 55-year-old is showing no symptoms, is in quarantine at home and that Saturday's training session had been cancelled.
"All other tests carried out by the squad and staff came back negative," it added. "Training ahead of the match with Napoli will resume on Monday, subject to the checks set out in the (Italian federation) protocol."
A number of Milan's squad are currently away with their respective national teams during the international break.
Several Milan players have previously tested positive and subsequently recovered including goalkeeper Gianluca Donnarumma and forward Zlatan Ibrahimovic.
Still unbeaten in the league, Milan lead with 17 points from seven games and face Napoli on November 22.