Barcelona midfielders Sergi Roberto and Andre Gomes will miss the next month after sustaining injuries during Tuesday's 0-0 draw at Olympiacos in Champions League Group D.
Roberto was replaced by Gerard Deulofeu during first-half stoppage time at the Karaiskakis Stadium and a statement released by Barca on Wednesday confirmed he will be sidelined for five weeks with a strain to his right hamstring.
Portugal international Gomes was introduced in place of Denis Suarez with 15 minutes remaining but suffered a thigh problem and is facing a three-to-four-week recovery timetable.
Roberto has become an increasingly important first-team member under Ernesto Valverde, making 16 appearances across all competitions for LaLiga's leaders this season.
Gomes has featured 11 times, although seven of those appearances have been as a substitute.
Barca remain top of their Champions League group, three points above Juventus and host Sevilla in LaLiga on Saturday.