Paris Saint-Germain beat Barcelona 4-2, but Ousmane Dembélé limped off in the 19th minute. Foot Mercato, citing L'Équipe, reported a left hamstring injury, while Khvicha Kvaratskhelia and Marquinhos also picked up injuries in the match.
Luis Enrique said the three injured players would undergo examinations.
Luis Enrique on the injuries
Luis Enrique said: "I am not a doctor. We have to wait until tomorrow to find out what the examinations they will undergo reveal. The injury of these three important players is the worst news. This is football at the highest level."
Report on Dembélé's condition
Foot Mercato, citing L'Équipe, reported that the injury could keep Dembélé out for two or three matches, with medical examinations set to confirm the diagnosis.
If that timeframe proves accurate, Dembélé would miss the clash with Lyon as well as the fixtures against Le Havre and Villarreal.
Rest periods and comments
Dembélé had joked with journalists after the win over Manchester City, saying: "There was the international break, and after it I went on holiday. And maybe I'll ask for another break if that's possible."
Luis Enrique said: "Ousmane is the boss. He jokes all the time, and I love his passion for football. Of course, it was a joke. I'm always open to giving players rest periods, that's my responsibility, but that means going to the training sessions at the club's centre."
Dembélé had been granted rest periods twice since the start of the season: after facing Rennes on 23 August, then after returning from the international break.
L'Équipe reported that Dembélé had spent his most recent break on a round trip to the United States of America. According to L'Équipe, Dembélé believes he needs to play in consecutive matches to recover his feel and rhythm.
Run of matches before the setback
Dembélé scored three goals and provided three assists across three Champions League matches.
He played against Manchester City, Strasbourg and Barcelona, but did not finish a third match in a row, limping off injured.