Luis Enrique's side currently sit in second place, four points adrift of Los Blancos, although Zinedine Zidane's men also have a game in hand due to their participation in the Club World Cup in December.
Barca beat Atletico Madrid 2-1 at the Vicente Calderon in the sides' Copa del Rey semi-final first leg on Wednesday and the two teams meet again on the same day next week, so Luis Enrique could rotate his pack ahead of that crunch clash.
Sergio Busquets and Andres Iniesta are both back in training, but the two midfielders have not been given the all-clear yet by the medical staff and may have to wait until the game against Atletico on Wednesday.
Lucas Digne also trained normally on Friday and the French defender may be in contention for a place after recovering from injury.
“In theory, they are back with the squad," Luis Enrique said in the pre-match press conference. "They trained today [Friday] and now we await the verdict of the medical staff. It’s great news to be able to have players back after injury."
Neymar is banned for the Copa del Rey second leg against Atletico on Wednesday, but the Brazilian is available for the Primera Division clash at home to Athletic on Saturday and Luis Enrique has no other suspensions to worry about ahead of the Liga game at Camp Nou.
BARCELONA POTENTIAL STARTING LINE-UP
Jasper Cillessen is Barcelona's goalkeeper in the Copa del Rey this term, but Marc-Andre Ter Stegen will return between the posts for the Liga clash on Saturday.
In defence, Digne is back from injury, but he is unlikely to be risked. On the right side of defence, however, there may be a start for the in-form Aleix Vidal.
Fit-again Busquets and Iniesta may play some part, but should start on the bench, with Lionel Messi, Luis Suarez and Neymar all in the team further forward.
ATHLETIC TEAM NEWS
Athletic sit seventh in La Liga, just two points behind sixth-placed Villarreal and only four adrift of Atletico in fourth. However, the Basque outfit have a poor record at Camp Nou and have also failed to win any of their last six away games in the Primera Division.
Coach Ernesto Valverde is sweating on the fitness of centre-back and one-time Barca target Aymeric Laporte, who missed training on Thursday and is doubtful for the Camp Nou clash.
Another defender, Eneko Boveda, trained alone and is set to miss out, along with forward Sabin Merino, who is recovering from a groin operation.
BEST OPTA MATCH FACTS
Barcelona have won six of their last seven games against Athletic in all competitions, with the other one ending in a draw.
In La Liga, Barcelona have won 12 in a row at Camp Nou against the Basque side - their best ever run at home against them.
Lionel Messi has had a hand in at least one goal in 20 of his last 25 games against Athletic in all competitions (20 goals, nine assists).
Aritz Aduriz has earned nine points for Athletic with his seven league goals, more than any other player for his team this term (same as Pedro Leon).
TV COVERAGE & KICK-OFF TIME
Barcelona against Athletic kicks off at 16:15 CET and as games cannot be televised in the UK at that time, the match will be shown later on in its entirety starting at 17:30 GMT on Sky Sports 5.