The world's most expensive player was injured while chasing forward Bouna Sarr and was seen crying as he was carried off near the end of the 3-0 win at the Parc de Princes.
He is set to miss the Champions League last 16 second-leg tie at home to Real Madrid on March 6 with PSG trailing 3-1.
Ligue 1 leaders PSG said on Monday that Neymar had suffered "a sprain of the right ankle and also a fracture of the fifth metatarsal" but did not say how long he would be sidelined.
Neymar, who joined PSG for 222-million euro ($273.39 million) from Barcelona in the close season, posted a picture of his heavily bandaged ankle on Instagram earlier on Monday.
The Brazilian has scored 28 times and provided 16 assists for PSG this season, although he gave a disappointing display against Real at the Bernabeu two weeks ago.
($1 = 0.8120 euros)
(Editing by Greg Stutchbury)
