Barcelona have confirmed that Jeremy Mathieu suffered a thigh strain in the 6-1 win over Villanovense on Wednesday.
The defender left the pitch during the closing stages of the comprehensive Copa del Rey victory at Camp Nou and was seen receiving treatment on the sidelines.
The Liga champions have since announced that medical tests conducted on Thursday have revealed a hyperextension to a muscle on his right thigh.
"His progress over the coming days will determine his availability for the next few matches," a Barca statement added.
Mathieu is likely to miss Saturday's away trip to former club Valencia, and could be a doubt for the Champions League game with Bayer Leverkusen on December 9 and the home clash with Deportivo La Coruna three days later.
Barca will hope to have him available for their first game in the Club World Cup in Tokyo on December 17.
