The Brazilian forward, 25, was photographed at a Paris nightclub in the early hours of Sunday morning.
Emery, however, insists he is not concerned about Neymar’s lifestyle.
The Spaniard said: “He is very responsible. In training, he is great.When he’s not on the pitch he can enjoy his time with his friends. He then comes back and plays well.
“We have to give the players the flexibility of living their own lifestyle. He is young, and he also needs to go out, but he is still responsible. He will be on the pitch against Celtic.”
PSG are already assured of a Champions League last-16 place but they want to finish top of Group B ahead of Bayern Munich.
The French giants showed their class on matchday one by rattling in five goals at Celtic Park and they will look to maintain that level in tonight’s clash in the Parc des Princes.
Emery said: “We want first position. To win the group we have to beat Celtic. We want to have the best performance possible and we want to play with the best players. Bayern are still in contention.