With Barca and Atleti playing each other on Saturday, Carlo Ancelotti's side will make ground on one or both of them if they can extend their unbeaten run over Espanyol to 12 games.
Espanyol have endured an inconsistent season under Javier Aguirre so far with only six league wins to their name, although one of those did come against Atletico at Estadi Cornella El Prat in October.
The Mexican may not be on the sidelines though after being sent to the stands during last week's 1-0 defeat to Osasuna, if he is found guilty of abusing the referee he could face a touchline ban starting this weekend.
The Portugal international is one of the most in-form players across the continent and is odds-on favourite to lift the FIFA Ballon D'Or on Monday after his displays in 2013.
"It is hard to think about what the best result (between Atletico and Barca) for us would be," the Italian said ahead of the match.
"They cannot both lose, but neither can they both win. We have to win to make up points with Barcelona or Atletico."
Espanyol have earned draws in their last two meetings with Real, however they come into the game on the back of consecutive defeats in the league and Wednesday's first-leg Copa del Rey tie with second -tier Alcorcon.
