Ousmane Dembele is several months apart after Barcelona confirmed he needed surgery on a knee injury at Euro 2020.
Sources have told ESPN that the France international will be out for three to five months, although Barca have not given a recovery timeframe.
Dembele, 24, left the France camp on Monday after suffering an injury in the final leg of Saturday's 1-1 draw against Hungary in Budapest.
"Following tests, it has been confirmed that he has a biceps tendon dislocation in his right knee that will require surgical treatment," Barca said in a brief statement on Tuesday.
Dembele has had bad luck with injuries since signing for Barca from Borussia Dortmund for a starting fee of €105 million in 2017.
A hamstring injury ruled him for four months into his first season at the club, while further muscle problems limited him to only nine appearances in all competitions in 2019-20.
However, the forward remained injury-free last season, playing 44 times and scoring 11 goals under Ronald Koeman.
His performances for Barca saw him recently recalled to France's squad and he has been off the bench in both his country's games so far at Euro 2020 against Germany and Hungary.
The latest blow comes at a time when his long-term future at Barcelona remains unknown.
Dembele's contract expires in 2022 and sources have told ESPN that Barca would have been open to offers for him this summer if he had not signed an extension.
Barca risk losing him next year for free if he doesn't sign a new deal, but is not interested until his knee is fully healed.