Paris St-Germain say they will take "appropriate action" after Brazil striker Neymar failed to turn up for the first day of pre-season training.
The 27-year-old was due back at the club's training ground on Monday. This forward has been linked with a move back to former club Barcelona.
"Paris St-Germain notes that Neymar Jr was not in attendance at the agreed time and place. This was without the club's prior authorisation," read a statement.
"The club regrets this situation."
What next for Neymar?
In an interview with La Parisien, PSG's sporting director Leonardo said: "Neymar can leave PSG, if there is an offer that suits everyone."
He added that there had been "very superficial contact" from Barcelona.
"But to date, we do not know if anyone wants to buy it or at what price," he added. "PSG wants to rely on players who want to stay and build something big."
Brazilian media quoted Neymar's father, Neymar Sr, as saying that PSG "were aware" that the forward was set to miss training on Monday because of charity commitments.
"The reason was known and planned for a year as part of his activities for the Neymar Institute," he told Fox Sports Brazil.
He will also miss the next three European matches for insulting officials.
The former Santos forward was stripped of the Brazilian captaincy in May before suffering an ankle ankle injury during an international friendly against Qatar last month that forced him to miss his country's Copa America triumph on home soil.
Source: BBC Sports