The Brazil striker left the pitch after an hour after receiving a knock and twisting his ankle, three weeks before PSG travel to Manchester United for their Champions League last-16 first leg.
PSG, who are runaway leaders in Ligue 1, are already sweating on the fitness of key midfielder Marco Verratti, who is suffering from an ankle injury.
Thomas Tuchel's side prevailed at the Parc des Princes thanks to a goal in each half from Edinson Cavani and Angel Di Maria.
Elsewhere, St Etienne slumped to a 6-3 home defeat to Dijon.
(Reporting by Julien Pretot; Editing by Toby Davis)
