Sergio Busquets faces a battle to be fit for the Champions League quarterfinals after breaking a bone in his foot during Barcelona's win over Chelsea on Wednesday.
Busquets, 29, had to go off in the second half and was replaced by Andre Gomes as Barca won 3-0 thanks to a brace from Lionel Messi and Ousmane Dembele's first goal for the club.
"Tests at the club's training ground on Thursday have confirmed that Busquets has broken a bone in his foot," a Barcelona statement said. "He is expected to be sidelined for three weeks."
Busquets will miss Sunday's La Liga game against Athletic Bilbao at the Camp Nou and will be unavailable for Spain during the international break.
Barca will also be without the midfielder for the trip to Sevilla on March 31 but may have him back for the first leg of the Champions League quarterfinals.
Ernesto Valverde's side will learn who they face in the next round when the draw is made on Friday, with the first leg to take place on either April 3 or April 4.
If Busquets does not recover in time for the first leg, he will almost certainly be available to face Leganes on April 7 and the second leg the following week.
He has been a mainstay this season, making 41 appearances in all competitions.
Nelson Semedo and Denis Suarez are Barca's only other injured players, although both should be back in contention by the beginning of next month.
Andres Iniesta returned from a hamstring problem to play over 50 minutes against Chelsea, and said after the game he had not yet decided whether to stay at the club or accept an offer from China at the end of the season.