PSG striker Neymar broke the ankle and sprained his ankle during his team's 1-0 victory over Olympique Marseille in the Ligue 1 on Sunday.
The world's most expensive player was chasing Marseille striker Bona Ser when he was injured and left the field on a stretcher near the end of the game, which ended 3-0 at Park de Prince.
He will miss the Champions League knockout round against Real Madrid on March 6. The Parisians lost 3-1 in the first leg in the Spanish capital.
Paris-St Germain said on Monday that Neymar was suffering from "a sprained right ankle and a fracture of the fifth bone in the instep" but did not say how long the Brazilian striker was missing.
Earlier on Monday, Neymar, who joined Paris St Germain from Barcelona for 222 million euros ($ 273.39 million) before the start of the season, posted a picture of his foot in his account on Ingestram, surrounded by many bandages.
Neymar scored 28 goals and made 16 with Paris St Germain this season, despite a disappointing performance against Real Madrid at Santiago Bernabeu two weeks ago.