
Eto'o was operated upon by doctor Ramon Cugat after tearing muscles and tendons in his right thigh in Wednesday's 5-0 thrashing of Inter Milan.
Cugat confirmed that the Cameroon forward would not be back in action until the beginning of December.
Cugat pointed out that this latest injury has nothing to do with the knee ligament injury that kept Eto'o on the sidelines for four months last season.
Barca coach Frank Rijkaard has replaced Eto'o in the squad for Sunday's home game against Athletic Bilbao with teenager Giovani dos Santos, who was the star of the show against Inter.
In addition to Eto'o, Barca also have Carles Puyol, Jose Edmilson and Eidur Gudjohnsen injured, though defender Gabriel Milito is now fit to make his debut.
DPA