The Brazilian picked up the injury against Eibar.
Philippe Coutinho came off the bench in the 2nd half but was forced off late on after picking up a problem.
The Brazilian has since undergone tests which have revealed that Coutinho requires surgery.
“The tests carried out on the first team player Coutinho have shown that the midfielder has an injury to the lateral meniscus in his left knee. Treatment will necessitate arthroscopic surgery which will take place in the coming days.
“The Brazilian came on in the 66th minute of the draw against Eibar in place of Miralem Pjanic but was unable to complete the game due to his injury which he picked up in injury time in the second half, leaving Barça with 10 men as they had already used their five permitted substitutes.”
Barcelona confirmed on Wednesday that Philippe Coutinho needs knee surgery after picking up an injury in the 1-1 draw against Eibar.
It’s not clear yet how long Coutinho will be out of action for, but the Brazilian joins Gerard Pique, Ansu Fati and Sergi Roberto on the injured list.