Ousmane Dembele is set to be out for two weeks after spraining his ankle in Barcelona’s 3-1 win over Leganes on Sunday.
The Spanish champions confirmed the news on Monday, and it will come as a blow to the club, with the France international impressing in recent weeks.
Dembele has sometimes struggled in Catalonia since his £97 million move from Borussia Dortmund in 2017, with general manager Pep Segura saying in November that he was still adapting to life at Barcelona.
However, the 21-year-old has been a key player recently, scoring six times in his last 10 outings.
He scored his 13th goal of the season on Sunday to set Barca on their way to the win that restored their five-point lead at the top of La Liga before being forced off in the 69th minute.
A Barcelona statement said: “Tests carried out on first-team player Ousmane Dembele have confirmed a sprained ankle that will keep him out of action for approximately 15 days.”
The injury means he is likely to miss both legs of their Copa del Rey quarter-final with Sevilla, and Sunday’s Catalan derby at Girona.
It is also possible he could be sidelined for the visit of Valencia at the beginning of February, although he should be fit for Barca’s Champions League last-16 meeting with Lyon next month.