Barcelona will be without Gerard Pique and Jordi Alba for the next few weeks after both defenders were taken off during Wednesday's 4-0 win over Manchester City in the Champions League.
Pique was withdrawn in the first half with an ankle problem after a loose challenge from Spain teammate David Silva.
The centre-half tried to play on initially, but was unable to do so and was eventually replaced by Jeremy Mathieu, who was later sent off for picking up two yellow cards.
After undergoing tests at the club's training ground on Thursday, Barca have confirmed that Pique will be missing for the next three weeks with a sprained ankle.
Alba, meanwhile, the club added, will be sidelined for two weeks after re-injuring his hamstring in the win against the Premier League leaders.
The left-back originally picked up the knock while on international duty with Spain earlier this month and missed last Saturday's game against Deportivo La Coruna.
However, he was cleared by the Blaugrana medical team to return on Wednesday, only for his hamstring to give way inside the opening 10 minutes. He was replaced by Lucas Digne.
Both players will miss Saturday's trip to Valencia and next weekend's league game against Granada at Camp Nou.
They will likely be unavailable for the trip to Man City on Nov. 1, too -- which Mathieu will also be suspended for -- but Alba could be back in contention for the game at Sevilla the following weekend.
Pique, though, is unlikely to be seen until after the November international break, when Barcelona host Malaga. He is also a doubt for Spain's games against Macedonia and England.
In better news for Barca boss Luis Enrique, Sergi Roberto is expected to be available at the Mestalla this weekend.
The right-back was cleared to return to action from an abductor injury against City, but Luis Enrique preferred not to risk him.