Madrid: Barcelona must overturn a terrible run of results away to Real Sociedad in recent years to prevent losing their grip on the Spanish title race when they visit Anoeta on Saturday.
Despite tasting defeat for the first time in 40 games on their last La Liga outing at home to Real Madrid last weekend, Barca still hold a commanding six-point lead over Atletico Madrid with Real a further point adrift and just seven games remaining.
However, the European champions haven't won in their last six trips to San Sebastian, including defeats in the last three seasons in La Liga.
"We have shown in recent years that we can beat Barca and we can do it again on Saturday," Real Sociedad's former Real Madrid midfielder Asier Illarramendi told the club's website.
"This team can beat anyone when we play well.
"Until it is mathematically decided Barca will have to fight and I am sure Atletico and Real Madrid won't give up."
Barca have particularly bad memories of their last visit to Anoeta as a 1-0 defeat plunged the club into crisis and left coach Luis Enrique on the verge of the sack.
Luis Enrique had left Lionel Messi and Neymar on the bench as a punishment for arriving back later than their teammates from their Christmas break.
Barca recovered in style from that setback to land the treble six months later, but their quest to become the first side to retain the Champions League could play a major role in the coach's selection as they hold a precarious 2-1 lead over Atletico heading into the second leg of their quarter-final tie on Wednesday.
Luis Suarez scored both Barca's goals against Atletico on Tuesday, but the Uruguayan will definitely miss out as he is suspended.
Munir El Haddadi is likely to replace Suarez with Sergi Roberto, Arda Turan and Rafinha -- who made his first appearance after a six-month injury layoff in midweek -- in contention to start in midfield.
Champions League considerations are likely to weigh heavily on the minds of Atletico and Real bosses Diego Simeone and Zinedine Zidane.
Atletico can close to within three points with victory at Espanyol before Barca kick-off on Saturday.
Fernando Torres looks certain to start as he will be suspended for the Champions League return leg after being sent-off having opened the scoring at the Camp Nou on Tuesday.
Real's hopes of an 11th European Cup also suffered a huge blow as they were shocked 2-0 by Wolfsburg on Wednesday leaving Zidane's men needing a monumental effort when the Germans visit the Santiago Bernabeu to progress to the last four.
Having admitted his side suffered physically after their efforts in the Clasico last weekend, Zidane is likely to ring the changes for the visit of Basque minnows Eibar on Saturday.
Karim Benzema is set to miss out despite the knee injury that forced him off against Wolfsburg being diagnosed as just a knock.
Dani Carvajal, Isco, James Rodriguez and Jese Rodriguez are all set to feature, but Gareth Bale and Cristiano Ronaldo are expected to start.
At the other end of the table, Valencia need to snap a run of four consecutive league defeats to ensure they aren't dragged into a relegation scrap when Sevilla visit the Mestalla seeking their first away win of the season.
Villarreal and Athletic Bilbao's Europa League commitments could also have serious consequences at the bottom as they host struggling Getafe and Rayo Vallecano respectively.