Barcelona have been hit by an injury crisis after their Copa triumph over Real Madrid.
Andres Iniesta and Alexis Sanchez both limped off in Wednesday night's 2-2 draw, which secured a 4-3 aggregate win.
That means Barca will head to Villarreal missing six players in total, as David Villa, Ibrahim Afellay and Andreu Fontas are already injured, while Seydou Keita is at the African Nations Cup.
"At the moment, we are not very many in number, but we must move forward," said coach Pep Guardiola.