Valencia pulled off arguably the shock of the season last week when they beat Barca at the Nou Camp to put a big dent in the Blaugrana's championship aspirations.
The slip-up means league leaders Atletico Madrid could extend their league over Barcelona to six points if they beat lowly Almeria on Saturday.
Barca will also find themselves level with Real Madrid by the time they play Sevilla if Carlo Ancelotti's side overcome Villarreal at the Santiago Bernabeu on Saturday evening.
Sevilla hardly go into Sunday's match on a great run of form themselves. The Andalucian side have not won in their last four matches, but that does not mean they will be frightened by the stellar opposition they will face, according to goalkeeper Beto.
"We are not the worst team in the world, I've always thought that, and we have always worked hard to get ourselves up the table," he told Sevilla's website.
"We can't stop doing that and we have to look upwards now. We have to look towards the next match with confidence and with respect but we cannot fear Barcelona.
"It's important to remember that we are playing at home, in front of our fans and we have to take the challenge head on with a positive and optimistic mentality. We have to be united and we have to believe we can win."
Atletico can achieve what Sevilla threatened to do towards the end of the previous decade - break up Barcelona and Real Madrid's duopoly of the Spanish league.
Sevilla finished third twice recently - first in 2007 and then two years later - but they have faltered recently, ending the most recent two campaigns in ninth.
For Barcelona to reassert their authority on the league, they must rediscover their form fast.
Gerardo Martino's men wilted against Valencia last weekend and they were far from convincing in their 2-0 win over Real Sociedad in the Copa del Rey on Wednesday.
Defender Gerard Pique hopes talisman Lionel Messi can rediscover his best form following his recent spell on the sidelines.
"Messi will start scoring goals again just like he has done all his life," the defender told AS.
"Leo can have two or three bad matches. He is human, like we all are.
"This is not the first time he has played not so well in several matches and then has gone on a stratospheric run.
"It always take time to get over injuries."
One man Barcelona will not be able to count on this weekend is Jordi Alba as the defender has had his appeal for his red card against Valencia rejected.
Barcelona did some good news earlier this week, though, when Neymar returned to training after three weeks out with an ankle injury.
The Brazilian, who has missed six matches in total, has been training away from the rest of the squad, but there is an outside chance the forward could feature against Sevilla, who have lost three times at home in the league this season.