Barcelona face Alaves on Saturday in the first match of the post-Ronald Koeman era without injured midfielder Sergi Roberto.
The Spaniard misses the Liga clash at the Camp Nou with “a right quadriceps strain” his club said.
“No date has been scheduled for a return as yet,” their statement added.
Roberto suffered multiple injuries last season, missing a total of 37 matches.
And his build-up to the 2021/22 campaign was hindered by a two-week absence after injury to his ribs.
Barca B coach Sergi Barjuan takes charge at Camp Nou after Koeman’s sacking on Wednesday following a 1-0 defeat by Rayo Vallecano at Vallecas.
Two wins in seven league games have left Barca languishing in ninth, nine points adrift of leaders Real Sociedad.