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.
"It will be a difficult and complicated task and because of this we will confront them with maximum concentration and knowing all the while that it is possible to take points and win at Barcelona."
Following Espanyol's disastrous start to the season, Javier Aguirre was brought in to replace Mauricio Pochettino at the end of last year and after three draws and one win under their new boss, Capdevila is hopeful that his side's fortunes are taking a turn for the better.
"We have started to see the light at the end of the tunnel but the road ahead is long and difficult," he said.
"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."