UEFA introduced the Financial Fair Play (FFP) rules to prevent clubs that qualify for its competitions from spending beyond their means.
Thomas Tuchel blasted Neymar for hitting a fan who insulted Paris Saint-Germain players as they filed up to collect their French Cup losers' medals.
As the players climbed the steps to receive their medals, shaking the hands of those nearby, Neymar, struck one of the fans in the face.
Neymar appeared to hit a fan on the chin following PSG's shock defeat to Rennes in the French Cup final.
Paris Saint-Germain were stunned by Rennes in Saturday's French Cup final, losing 5-6 on penalties after a dramatic game finished 2-2 at the end of extra time.
Qatar-backed PSG are now 16 points ahead of Lille who have five games to play.
The three-time World Cup winner was discharged late Monday from the private American hospital in the Paris suburbs.
Edinson Cavani has scored 17 times in the French league and twice in the Champions League this season.
Images and videos of Neymar's birthday bash are taking the Internet by storm.
Neymar would be out for 10 weeks with a metatarsal injury.
The world's most expensive player left the field in PSG's French Cup win over Strasbourg on Wednesday.
PSG coach Thomas Tuchel said his side need to "stay humble" after reaching the Champions League knockout stage.
PSG have quashed reports the club could be forced to sell either Kylian Mbappe or Neymar in a bid to circumvent eventual FFP sanctions.
Juan Bernat and Neymar scored to put PSG in control in the first half in the French capital.
Fitness of Kylian Mbappe and Neymar casts the longest shadow over PSG ahead of Wednesday's Champions League crunch clash against Liverpool.
Cristiano Ronaldo and Lionel Messi have won the Ballon d'Or five-time each while Paul Pogba won the FIFA World Cup 2018 with France.
Neymar is nursing a strained adductor muscle in his groin while Kylian Mbappe is suffering from a shoulder contusion.
A Spanish magistrate leading an investigation into alleged irregularities in Neymar's move to Barcelona in 2013 said the footballer could face up to six years in prison.