“In compliance with the legislation and in agreement with the local health authority, the team group has entered into fiduciary isolation as of today,” the club said in a statement.
People testing negative could carry out regular training and match activities, but would not be allowed contact outside the group, it added.
Rafia, a 22-year-old Tunisia international, has made one senior appearance for Juventus since arriving from Olympique Lyonnais in July 2019.
Massimiliano Allegri’s side are scheduled to face Monza in a friendly on Saturday July 31, before taking on Barcelona at the Camp Nou in their final pre-season match on August 8.
Juve’s bid to reclaim the Serie A title from Inter Milan starts with a trip to Udinese on August 22.