Barcelona lost defender Sergino Dest to injury during the team’s 2-1 Europa League win over Galatasaray on Thursday night in Istanbul.
The USMNT star started the game but was forced off on 56 minutes and replaced by Ronald Araujo with what appeared to be a hamstring problem.
It’s a tough blow for Dest who had been enjoying a strong game against Galatasaray and has looked much-improved in recent weeks.
Dest now looks to be a real doubt for Sunday’s Clasico against Real Madrid, although Xavi may have been planning to start Dani Alves at right-back in any case at the Bernabeu.