The Madrid supremo feels the reigning champions must not give up hopes of holding on to their title just yet as a lot can still happen between now and the end of the season
The Blancos currently sit second in the Primera Division table, trailing the Catalan giants by 13 points with 10 more games to go.
Nevertheless, Perez has made it clear anything can happen between now and the end of the season and has demanded of his players that they do not give up the fight just yet.
"We need to put pressure on Barcelona. I don't care if we end up 10 points behind; we have to keep trying until the end," the Madrid president was quoted as saying by Marca.
"We have to believe it's possible. We can't give up and we need to think about the supporters who go to the matches and the fact that they do believe."
Madrid take on Zaragoza at La Romareda on March 30 as they aim to close the gap on Barca.