Striker Neymar absent for 1st day of PSG preseason training
PSG said in a statement that "Neymar was not in attendance at the agreed time and place" and this was "without the club's prior authorization."
Neymar could face disciplinary procedures. PSG said "it regrets this situation and will therefore take appropriate action."
He cost a world record 222 million euros ($249 million) from Barcelona two years ago.
But his two seasons at PSG have been blighted by injuries to his right foot and he has been linked with a reported move back to the Spanish champion.
The 27-year-old Neymar missed Brazil's successful Copa America campaign because of an ankle injury.
A Brazilian model accused him of raping her in a Paris hotel on May 15. Neymar denies any wrongdoing.