Barcelona have confirmed Sergio Busquets suffered ankle ligament damage during Sunday's LaLiga match at Eibar.
Busquets left the field on a stretcher after 10 minutes following a rash tackle from Gonzalo Escalante.
During the second half of the match at Ipurua, the club tweeted to announce the Spain international midfielder had a sprained external lateral ligament in his right ankle.
Busquets will have further tests on the injury on Monday.
Luis Enrique's side were already without Andres Iniesta at Eibar after their club captain suffered a calf injury during the midweek Copa del Rey win at Real Sociedad.