Neymar reportedly suffered a thigh strain playing for Brazil against Cameroon in an international friendly on Tuesday, with the Paris Saint-Germain star leaving the field of play after only six minutes.
Matt Barlow of the Daily Mail reported an injury that will concern PSG fans ahead of their UEFA Champions League clash with Liverpool on November 28.
The forward's game ended prematurely in Milton Keynes when he attempted a cross into the box early in the contest.
Neymar immediately signalled he had injured his leg and was given treatment on the pitch.
The former Barcelona player got to his feet and hobbled to the touchline, and the decision to substitute him was made swiftly.
Everton attacker Richarlison took Neymar's place, with fans at Stadium MK clearly disappointed by the turn of events.
PSG are set to face Toulouse in Ligue 1 in the French capital in their next game on Saturday, but then host the crucial European fixture against the Anfield giants.
Kylian Mbappe was also substituted with an injury for France, making it a terrible night for the Ligue 1 giants, per football writer Matt Spiro:
It's a match the French champions cannot afford to lose, with Group C in the balance after four matches.
A loss could see PSG crash out of the competition, forcing them to compete for a third-place UEFA Europa League berth.