The former Spain international is optimistic los Periquitos can take something away from their visit to the Camp Nou this weekend despite Barca's impressive form.
The Catalans have been in fine form this season and have conceded just two points from their 17 matches played so far.
In contrast, Espanyol are third from bottom with just 15 points to their name.
However, Capdevila, who is a World Cup and European Championship winner with Spain, is optimistic of his side's chances when they meet Barca at Camp Nou.
"Barcelona are the leaders in the table and are away ahead of the rest. But, some day they will have to lose. They will not always win," Capdevila told Marca.
"We are very conscience of the team we face, they are having a great moment and they are a great team. But, eventually they will concede points and we will try to make them cede some points this Sunday.
"A good result against Barcelona will help to push us up the table, but there will still be much more work to do. However, a win will be a great boost."