Paris Saint-Germain winger Kvicha Kvaratskhelia is set to have surgery after rupturing his anterior cruciate ligament (ACL), the French club have confirmed.
The 25-year-old, who was named the Champions League's best player last season, was injured in Tuesday's 4-2 home win over Barcelona.
The European champions have said Kvaratskhelia will have an operation "in the coming days" but gave no timeline for his recovery.
The injury raises serious concerns over whether Kvaratskhelia will play again this season, but he will definitely miss PSG's Champions League trip to Aston Villa on December 8.
Kvaratskhelia has been nominated for the 2026 Ballon d'Or after a stellar campaign last season as he helped PSG earn back-to-back Champions League titles as well as Ligue 1 glory.
The Georgia captain's injury setback is a major blow for PSG, who are in pursuit of a third straight Champions League crown.
Kvaratskhelia has emerged as one of the world's leading forwards since joining the French champions from Napoli for £59m plus add-ons in January 2025.
Dembele and Marquinhos also suffer injuries
PSG also lost Ousmane Dembele, the reigning Ballon d'Or holder, and captain Marquinhos to injury against Barca.
The French club's statement says both players have thigh injuries and "will remain under treatment for the next few weeks".
Another key player, Nuno Mendes, is also injured after missing the win over the Spanish champions following an injury in PSG's Ligue 1 win at Strasbourg on Saturday.
PSG have been in scintillating form in Europe this season since defending their title in May, beating Manchester City and Barcelona by the same 4-2 scoreline this month.
Luis Enrique's side are top of the 36-team league table after three wins from three, while they sit second in Ligue 1, level on points with leaders Lyon.