The three players were fined and left out of Pirlo's squad for Saturday's 2-2 Turin derby draw with Torino after breaking national protocols on Wednesday.
United States midfielder McKennie hosted a dinner party in the hills above Turin, with Dybala and Arthur among 10 guests in attendance.
Italian rules restrict the number of people allowed in a home and enforce a curfew from 10 p.m. to 5 a.m.
The fitness of the three players will now be assessed ahead of Napoli's visit.
Juve are in fourth place in the table, 12 points adrift of leaders Inter Milan and level on 56 points with Gennaro Gattuso's Napoli side who are one spot below them.