A run of three games without victory has ended any hopes Real had of winning La Liga, so their meeting with Javier Aguirre's side represents little more than an undercard clash ahead of the title-deciding bout between their arch-rivals Barcelona and Atletico Madrid, which kicks off two hours later.
Carlo Ancelotti's men have taken just two points from their last three league fixtures, meaning they have gone more than two Liga games without winning for the first time since May 2009.
Real's poor run of domestic form has followed their stunning 4-0 UEFA Champions League semi-final second-leg demolition of Bayern Munich.
And it is safe to say Ancelotti will now have more than one eye on next Saturday's Champions League showpiece with neighbours Atletico, when Real go in search of their long-awaited 10th European crown.
That could mean top scorer Cristiano Ronaldo, who missed last Sunday's 2-0 defeat at Celta Vigo with a hamstring problem, is rested for the dead rubber against Espanyol.
However, the FIFA Ballon d'Or winner - who has scored 50 goals in all competitions this season - is sure to be keen to play, as he requires just one more strike to overtake Liverpool's Luis Suarez in the race for the European Golden Shoe.
Aguirre's team have won just one of their last 10 Liga fixtures - a 2-1 victory at Malaga on March 25 - and appear to already be focused on their end-of-season holidays.
Furthermore, Espanyol have not won at the Bernabeu since April 1996, and have been beaten 1-0 by Real on three occasions already this season - once in La Liga, and twice in the clubs' Copa del Rey quarter-final meetings.
