Barcelona were facing an injury crisis as well as a results crisis on Sunday after defenders Gerard Pique and Sergi Roberto were ruled out for significant periods following injuries sustained in Saturday's 1-0 La Liga defeat by Atletico Madrid.
A Barca medical report said veteran centre back Pique, who limped off the pitch in the second half in tears, had sprained the internal lateral ligament in his right knee as well as sustaining a partial injury to the anterior crucial ligament.
The statement did not state how long Pique would be out for but reports in the Spanish media estimated he would be out for between three and five months.
Right back Sergi Roberto, meanwhile, ruptured a muscle in his thigh and would be out for two months, added Barca.
The loss of the two defenders add to previous injuries to Samuel Umtiti and Ronald Araujo and leave coach Ronald Koeman with only three defenders (Clement Lenglet, Jordi Alba and Sergino Dest) available for Tuesday's Champions League trip to Dynamo Kiev.
Barca will also be without forward Ansu Fati for the next four months after he underwent knee surgery earlier this month, while midfielder Sergio Busquets is out with a knee problem but is due back by the end of the month.
Yannick Carrasco's goal for Atletico inflicted a third defeat in eight league games on Barca, who are 10th in the standings, nine points adrift of second-placed Atleti and leaders Real Sociedad.
