Ousmane Dembélé was substituted after just 26 minutes for Barcelona against Girona in La Liga on Saturday.
It remains to be seen what type of injury the French winger has picked up, but early reports suggest it could be a muscular problem.
The 25-year-old was seen with ice on his leg as Barcelona looked to break the deadlock against their Catalan rivals.
Dembélé had been in fine form for the Blaugrana recently, with a superb showing against Real Sociedad in the Copa del Rey at Camp Nou in midweek.
It was 0-0 at the time of the change. Pedri, who was initially rested by Xavi, replaced the winger.