Holders Barcelona will aim to snuff out the slim prospect of an early Copa del Rey exit when they host Segunda B outfit Villanovense on Wednesday.
A second-string Barca line-up were unable to find a way past their third-tier opponents when the first leg finished goalless in October.
An attack led by Munir el Haddadi and Sandro Ramirez failed to fire and head coach Luis Enrique must ponder whether to name the likes of Ballon d'Or nominees Lionel Messi and Neymar in his squad in case the threat of an improbable upset begins to loom larger.
"I hope our best moment is still to come," Luis Enrique told reporters after the Sociedad match.
"That we are playing well and that the team is enjoying themselves is undeniable. But nobody wins anything in December.
"We have an important month coming up, with big games in La Liga, the Club World Cup and the Copa del Rey. We have to take it game by game."
A 2-1 loss to Cartagena on Saturday was their fifth in succession since playing Barcelona and leaves Julio Cobos Moreno's team mired in Segunda B Group 4 relegation trouble.
The last-32 clash will be completed ahead of schedule due to Barca's forthcoming participation in the Club World Cup.
