Real Madrid stalwart Iker Casillas has warned his teammates that they could still lose out to Barcelona in the Primera Division title race.

Madrid couldn't find a way past Valencia last night, cutting their lead over Barca to just four points.

However, Casillas is keen to ensure that his side focus on winning their remaining games, starting with the derby against Atletico Madrid on Wednesday, and not on the fact that they were once 10 points clear.

"Mentality is very important. The lead we had has been reduced, but we shouldn't cry about it. We have a large lead, but it isn't definitive and we must continue focusing on one game at a time," said the veteran goalkeeper.

"We must focus on winning against Atletico Madrid. This moves very quickly and we play many games in few days. We have to go on. Every match is vital and they'll all be like finals, so we'll think about Bayern Munich [in the Champions League semi-finals], Sporting [Gijon] and Barcelona after facing Atletico, who are the ones that matter to us right now.

"We cannot live just on the fact that our lead used to be 10 and eight points strong."

Casillas has been at Madrid his entire career, making 617 appearances for the club and winning four league titles in that time.