The loss at the Bernabeu saw Barca relinquish first spot in the table to Los Blancos. Sociedad, meanwhile, have won their last three in Spain's top flight to rise into sixth position.
Barca have not been without their problems this season, but they are very much in the title race heading into the home straight, sitting just one point off division leaders Real Madrid on the same number of matches.
Quique Setien's side would have been looking to strengthen their grip on first when they travelled to the Bernabeu last weekend, but the home side managed to record a two-goal victory.
The loss in the Spanish capital followed a 1-1 draw away to Napoli in the first leg of their last-16 Champions League clash on February 25, meaning that there is work to be done if the Spanish champions are to progress to the quarter-finals of the European Cup.
There is enormous pressure on Lionel Messi to ensure that Barca finish the season strongly, and there is no question that the Catalan giants will be desperate to return to winning ways this weekend.
Incredibly, the reigning champions have won their last 19 home games against Sociedad in all competitions, while they have been victorious in 19 of their last 20 home matches in Spain's top flight.
Sociedad, though, will bring serious form into this contest. Indeed, the Basque outfit have won four of their last five in Spain's top flight, including their last three against Athletic Bilbao, Valencia and Real Valladolid.
They have only conceded once in their last three matches, meanwhile, and currently sit sixth in the table, just two points behind fourth-placed Getafe as the race for the Champions League heads for the home straight.
Sociedad are only actually three points off third-placed Sevilla, and a victory at Camp Nou on Saturday evening is certainly not beyond Imanol Alguacil's side considering their form.
Barca have also only kept three clean sheets in their 11 competitive matches under Setien, and Sociedad have the firepower to cause all sorts of issues in this match with Portu, Mikel Oyarzabal, Willian Jose and Alexander Isak all among the goals during the 2019-20 campaign.
Alguacil's team also booked their spot in the final of the Copa del Rey on Wednesday night as a 1-0 success over Mirandes in the second leg of their semi-final saw them progress 3-1 on aggregate.
Barcelona La Liga form: LWWWWL
Barcelona form (all competitions): LWWWDL
Real Sociedad La Liga form: LWLWWW
Real Sociedad form (all competitions): WWWWWW
Willian Jose replaced Isak in the starting XI against Mirandes on Wednesday night, but the former is expected to return to the starting XI for this weekend's match.
Ex-Manchester United attacker Adnan Januzaj should also keep his spot in an attacking position, while there are unlikely to be changes in defence with former Arsenal defender Nacho Monreal again lining up at left-back.
Barcelona possible starting lineup:
Ter Stegen; Semedo, Pique, Lenglet, Alba; De Jong, Busquets, Arthur; Fati, Griezmann, Messi
Real Sociedad possible starting lineup:
Remiro; Zaldua, Elustondo, Le Normand, Monreal; Merino, Zubeldia, Odegaard; Oyarzabal, Isak, Januzaj
We say: Barcelona 2-1 Real Sociedad
This is threatening to be another very, very difficult game for Barca. Sociedad will arrive full of purpose having won their last six matches in all competitions, but we just fancy the hosts to record a narrow victory.