Paulo Dybala, Weston McKennie and Arthur Melo were reported to have been fined by police who were called by neighbours to the lockdown get-together at US midfielder McKennie's Turin home.
Turkey defender Merih Demiral also tested positive while with his national side and returned to Turin on a medical flight, the team said.
Champions League: Andrea Pirlo's Juventus slammed as 'clueless and devoid of ideas' after Porto defeat
Corriere Dello Sport branded the defeat as Juventus' "worst match of the season". The Italian newspaper blasted the Turin side as "distracted and superficial" while describing star striker Cristiano Ronaldo as "a ghost".
Both Dybala and Bonucci will nevertheless make the trip to Portugal "because they all want to be close to the team," said manager Andrea Pirlo.
Serie A: Cristiano Ronaldo, Leonardo Bonucci apologise for 'worst' Juventus performance of season against Fiorentina
Andrea Pirlo's Juventus have won just six of their 13 league games this season, with six draws and one defeat.
Before Juve's game in Turin, Cristiano Ronaldo was presented with a special jersey commemorating his 750th career goal. Before Juve's game in Turin, Cristiano Ronaldo was presented with a special jersey commemorating his 750th career goal.
However, it is still far from certain whether the government will allow Serie A to complete the season.
Ivan Juric’s side left the Juventus stunned as Fabio Borini struck an equaliser before a late penalty from substitute Giampaolo Pazzini completed the comeback.
Serie A: On employing 'Sari-ball' at Juventus, coach Maurizio Sarri says he can't 'redo' tactics he used with previous teams
With the likes of Cristiano Ronaldo in attack plus Leonardo Bonucci and Matthijs de Ligt in defence, Juventus possesses more talent than any other squad that Sarri has coached
Atletico and Juve have a point each while Lokomotiv Moscow top Group D after beating Bayer Leverkusen 2-1 away from home
Veteran Juventus captain Giorgio Chiellini will undergo surgery after tearing a ligament in his right knee in training.
Cagliari have escaped punishment by Italian football authorites for racist abuse directed by their fans at Juventus striker Moise Kean during a league game last month, the Lega Serie A announced on Tuesday.
Champions League: Serie A leaders Juventus put domestic responsibilities on back-burner to focus efforts on youthful Ajax side
Juventus have put their bid to wrap up an eighth consecutive Serie A title on the back burner as they focus on their European ambitions
Champions League: Cristiano Ronaldo could be back for Ajax showdown, says Juventus manager Massimiliano Allegri
Cristiano Ronaldo could be back in the Juventus line-up in time for their Champions League quarter-final with Ajax, coach Massimiliano Allegri revealed.
Moise Kean racism row: Possible punishment should fit the crime as racial discrimination resurfaces in Italian football
Moise Kean racism row gives us an insight into Italy’s institutionalised racism and tolerance for intolerance and backward mentality
Serie A: Leonardo Bonucci condemns all forms of racism, says his comments after Juventus game were 'misunderstood'
Under-fire Juventus centre-back Leonardo Bonucci said Wednesday he had been "too hasty" when blaming young teammate Moise Kean for being partly responsible for racist insults hurled at him in a Serie A game at Cagliari.
Yaya Toure, Raheem Sterling slam Leonardo Bonucci, Massimiliano Allegri's response to racist abuse of Moise Kean
Yaya Toure and Raheem Sterling slammed Massimiliano Allegri and Leonardo Bonucci after they said Moise Kean shared the blame for racist abuse by Cagliari fans.
Serie A: Racist chants mar Juventus’ win at Cagliari as Moise Kean continues goal-scoring spree; Udinese hold AC Milan
Rising Italy star Moise Kean was targeted by racist abuse after he continued his goal-scoring spree to push Juventus closer to an eighth consecutive Serie A title on Tuesday with a 2-0 win over Cagliari.
Euro 2020 qualifiers: Fabio Quagliarella becomes oldest ever player to score for Italy in crushing victory over Liechtenstein
Fabio Quagliarella became the oldest ever player to score for Italy as the 36-year-old converted two penalties in a crushing 6-0 Euro 2020 qualifying win by the Azzurri over Liechtenstein on Tuesday.
Serie A: Cristiano Ronaldo shines in Juventus cruise against Frosinone as Atletico Madrid await in the Champions League
Cristiano Ronaldo set up Paulo Dybala to score early and added one himself with defender Leonardo Bonucci also on target as Juventus surged 14 points clear in Serie A on Friday with a 3-0 win over lowly Frosinone.