Luciano Spalletti's side are one of four teams vying for one of the two remaining Champions League places, but the players were still in the changing room when their top four rivals kicked off their fixtures.
Juve's hardcore fans have demanded that the match be suspended after one of their number suffered what local media are calling serious, but not life-threatening, injuries in the brawl.
The other four matches involving teams chasing the top four or trying to avoid relegation were delayed by around five minutes as the fixtures were supposed to all kick off at the same time.
But the fixtures involving third-placed AC Milan, Roma and Como, who are level on 68 points with Juve in fifth, kicked off while Juve's match was still yet to start.
Two points separated sixth-placed Juve from the Champions league spots heading into this season's final round of fixtures.
© 2026 AFP