With Real Madrid trailing by 11 points, Barcelona's closest threat is from Atletico Madrid who they face today, and midfielder Xavi Hernandez feels it is an opportunity to dent their title aspirations.
Barca have made a record start to the season with a remarkable 14 wins from 15 games and while the reigning champions and traditional rivals Real Madrid have not been able to maintain the pace it has been Atletico who have made an impressive start and trail the Catalans by seven points.
"It is too early to really say who are going to be the biggest rival and at the moment it looks as though both will be strong rivals," Xavi said.
"Atletico are very strong. People said that they were going to slip-up but they haven't very much and now this weekend we have our chance to make them slip-up.
"They are on a good run, they play very well on the counter-attack and they have a striker [Radamel] Falcao who motivates them all. Their trainer [Diego] Simeone has worked very well with the team and they have a strong defence.
"At the same time, though, while Atletico are the nearest rivals at the moment Madrid are not out of the running by any stretch of the imagination."
Falcao hit five goals last weekend as Atletico demolished Deportivo La Coruna 6-0 and he now has 16 league goals.
Real Madrid, meanwhile, continue to stutter with Mesut Ozil coming to the rescue with a brace as they beat Valladolid 3-2 and then in midweek they lost 2-1 away in the first leg of a King's Cup game with Celta Vigo.
They now take on Espanyol, who are joint bottom with Deportivo La Coruna, and while new coach Javier Aguirre has been working on their defence, it should be a relatively easy game.