Philippe Coutinho will undergo knee surgery on Saturday, Barcelona have announced, as reports in Spain suggest he could be out for several months.
The Brazil international was introduced as a 66th-minute substitute during Tuesday's disappointing 1-1 draw with Eibar at Camp Nou, but was unable to see the game out.
On Friday, Barca confirmed the Brazil international will have an operation on the external meniscus of his left knee, after which a timetable for his return will be revealed.
A club statement read: "Philippe Coutinho will be operated on this Saturday for the injury to the external meniscus of the left knee by Dr. Joan Carles Monllau and under the supervision of the club's medical services.
"Once the surgery has been completed, further information will be provided to detail the approximate expected recovery time."
Several Spanish media outlets have reported the 28-year-old is likely to be out of action for an extended period of time, potentially not playing again until April.
Such a lengthy absence would be another blow for Barca boss Ronald Koeman, who is already without Ansu Fati, Sergi Roberto and Gerard Pique through injury.
Coutinho has made 14 appearances for Barcelona this season in all competitions, scoring three goals and providing two assists. He spent the previous season on loan at Bayern Munich, helping the German club secure a treble that included winning the Champions League.
Rumours had circulated he could leave the club in the January transfer window, but this latest setback looks to have ensured he will see out the 2020-21 campaign in Spain.