Ousmane Dembele will need surgery on the knee injury he suffered while on duty with France at Euro 2020.
The Barcelona winger was hurt after coming on as a substitute for Les Bleus in the 1-1 draw with Hungary, managing just 30 minutes on the pitch before being replaced by Thomas Lemar on Saturday.
After undergoing scans, France confirmed on Monday that Dembele would be unable to play any further part in the tournament.
His club have carried out further tests on the issue, revealing a dislocation of the biceps tendon in his right knee. In a statement on Tuesday, Barca announced the player will require surgical treatment.
While no timetable was provided for his recovery, reports in the Spanish media suggest he could be sidelined for three to four months.
Dembele's career since his move to Barca from Borussia Dortmund for €105million four years ago has been blighted by injury setbacks.
The 24-year-old has managed just 54 LaLiga starts in four seasons at Camp Nou, while last season he completed 90 minutes in the league on just five occasions.
Barcelona have strengthened their attacking options for the 2021-22 season with the additions of Sergio Aguero and Memphis Depay, both forwards joining on free transfers.