Barcelona says goalkeeper Claudio Bravo has injured his right leg with two more rounds left to decide the Spanish league title.
The Chile goalkeeper was replaced by Marc-Andre ter Stegen late in Barcelona's 2-0 win at Real Betis on Saturday that kept Barca top of the table.
Barcelona says tests have revealed an injury in Bravo's right leg, adding that the speed of his recovery would determine if he will be ready to play next Saturday against Espanyol.
Barcelona will finish the season the following weekend at Granada.
The Catalan club is level on points with second-place Atletico Madrid, with Barcelona ahead on head-to-head advantage. Real Madrid is one point behind.
Bravo starts in the league, while Ter Stegen plays in the cup competitions.