Although the outcome of the two Copa del Rey games was never in doubt after the first leg, thanks to Antoine Griezmann's late equaliser in the second game, Barca have still not won at the Anoeta Stadium since 2007.
Given the closeness of the title race in La Liga, you can be assured that Tata Martino won't be taking any chances as far as staffing is concerned in this one.
Arrasate by contrast, will be making another huge mistake if he is only willing to rely on the prowess of Griezmann and Carlos Vela.
Both have been shining lights in the Sociedad team this season, but the manager needs the full XI to step up and put in a shift.
In the last game, Barca were content to knock the ball around and hit La Real on the break, and 76 percent possession across the entirety of the match (per whoscored.com) is a fairly accurate indicator of just how poor Sociedad were in that match.
With only a handful of points separating them from a European place, this has to be regarded as a must win game from Sociedad's point of view also, and their game plan must legislate for this accordingly.
A resumption of the previous tactics used against the Blaugrana will tell us much about the ambitions of the Txuri-urdin.
Lionel Messi has shown just how well he has recovered from his latest injury; goals and assists aplenty have flowed as usual.
Even the presence of five defenders couldn't stop the Argentine scoring a stunning individual effort when the teams last met and Martino will be looking for more of the same from his main man again.
It may well be that Pedro's speed gets him the nod over Alexis Sanchez on the right side, despite an acceptable performance from the Chilean against City.
Sociedad's left-back Jose Angel is lacking confidence at the moment and the speed of the Canary Islander will unnerve him further.
After Tuesday's exertions Xavi Hernandez may be rested again, but in Cesc Fabregas Barca have an in-form and more than able utility man to slot in again alongside "El Illusionista" Andres Iniesta.
Iniesta is beginning to show the form of the last couple of seasons once more, his expert shielding of the ball and crafty interplay an absolute joy to behold.
There is absolutely no reason to expect anyone other than Sergio Busquets filling the holding role that he has made his own since 2008.
A 98 percent pass accuracy and 119 touches in the last game (per whoscored.com) between the two is astonishing statistics for a defensive midfielder but accurately determines his (often unnoticed) influence in games.
Despite recently turning down a new contract because he wants assurances on the amount of games per season he will play (per Jamie Sanderson of Metro), Martin Montoya will not dislodge Dani Alves for this one.
The Brazilian was a constant thorn in Sociedad's side in that last game and Martino will want to continue the theme.
Gerard Pique and Javier Mascherano will continue their partnership after a magnificent performance in Manchester. Both have had their critics this season but they were literally head and shoulders above everyone at the Etihad Stadium.
Vela and Griezmann might feel they have a decent chance to impress against the two, and we may see some early pressure to break Barca's stride. Much will depend on which version of Pique and Mascherano turn up.
Adriano Correia will replace Alba on the left side and will be tasked with terrorising Xabi Prieto and Zaldua for the duration, whilst Victor Valdes will take the reins in the Barcelona goal as he counts down the last few games of his Blaugrana career.
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