The Polish player was forced to leave the game after hurting his left hamstring, which is a crucial muscle in the leg.
The club has not yet revealed how long Lewandowski will be out, but it's feared that he might miss several games, including the Copa del Rey final against Real Madrid next week.
This could also affect his participation in the Champions League semifinals against Inter Milan in late April and early May.
Lewandowski has been a key player for Barcelona this season, scoring 40 goals in 48 competitive matches.
