Marc-Andre ter Stegen suffered an injury during training on Friday, leaving Jasper Cillessen in line to take the gloves against Alaves.
Cillessen joined the LaLiga champions from Ajax shortly before the closure of the transfer window, replacing Claudio Bravo, who moved to Manchester City.
The Netherlands international is expected to get his chance in goal after Ter Stegen sustained a hamstring injury, which meant he was not named in Luis Enrique's match squad on Saturday morning.
Jordi Masip is the other goalkeeping option available to the Barcelona boss.
Lionel Messi is included after aggravating a groin complaint while playing for Argentina, while Portugal midfielder Andre Gomes has shaken off a muscular problem sustained during the international break.
Captain Andres Iniesta (knee) and defender Jeremy Mathieu (hamstring) are available to return to action for the first time since the first leg of the Supercopa de Espana win over Sevilla.
Defensive duo Gerard Pique and Sergi Roberto will be rested, with Neymar not deemed ready to return following his lengthy spell away with Brazil at the Olympics.
In his absence, new recruit Paco Alcacer could feature in attack and join Cillessen in making his debut.