The home team have 14 points and their 0-0 draw with Osasuna on December 14 left them two points from 17th-placed Deportivo Alaves - who occupy the league's final safety spot - while the visitors lost 1-0 against Real Valladolid on December 13 and have just 10 points after 15 matchweeks.
Match preview
Espanyol's match against Osasuna was a remarkably dull affair given neither side managed to create a big chance, though boss Manolo Gonzalez will at least be pleased that his goalkeeper did not have to make a single save.
Gonzalez's team had not kept a clean sheet in any of their prior five fixtures and had only prevented their opponents from scoring three times in their 18 games this season.
Blanc-i-blaus have netted 15 goals and conceded on 28 occasions in La Liga, and these records make them the division's fourth-worst offensive and joint second-worst defensive club.
To their credit, Espanyol have collected four points from their last three league outings, but they did lose seven of the previous eight top-flight matches.
The hosts' form at home this season has been quite strong considering they have triumphed in four of their seven most recent La Liga games at RCDE Stadium, drawing once and losing twice in that period.
As for Valencia, fans will be bitterly disappointed that their team were beaten by Real Valladolid, who scored from their only shot on target in the 20th minute and were also reduced to 10 men in the 78th minute.
Los Ches have not competed in the second tier of Spanish football since the 1986-87 season, but they are on track to tally just 25 points this term, their lowest La Liga total since they were relegated at the end of the 1985-86 campaign.
Manager Ruben Baraja's side are the top flight's third-worst offensive team having scored just 13 goals, although their record of 1.5 goals conceded per match is only the league's joint seventh-worst defensive return.
The visitors have won three of their last six games in all competitions - losing their two most recent matches - but they have been defeated in each of their past three La Liga fixtures and have only triumphed in one of their last nine league outings.
Baraja will also be alarmed by his team's away form in the top flight given they have lost eight and drawn three of their 11 most recent games on the road.
Espanyol La Liga form:
L
L
L
W
L
D
Espanyol form (all competitions):
L
L
W
L
L
D
Valencia La Liga form:
L
D
W
L
L
L
Valencia form (all competitions):
Team News
Espanyol will not be able to select midfielders Pol Lozano and Jose Gragera due to suspension and injury respectively, and the latter will not be available until January.
Alex Kral started with Lozano in a double pivot against Osasuna, but he may be partnered by teenager Rafael Bauza on Wednesday.
Centre-back Marash Kumbulla is also suspended, so Gonzalez could start Leandro Cabrera and Sergi Gomez in his absence.
Meanwhile, full-back Thierry Correia will not appear for Valencia until sometime next season as a result of a cruciate ligament injury that he sustained in early November, while Jose Gaya will not return until early January.
Centre-back Mouctar Diakhaby is a doubt and goalkeeper Giorgi Mamardashvili is set to miss out until late December, so expect Baraja to field a back four consisting of Dimitri Foulquier, Cesar Tarrega, Cristhian Mosquera and Jesus Vazquez in front of Stole Dimitrievski.
Pepelu and Javier Guerra are likely to start in midfield behind a front two featuring Diego Lopez and Hugo Duro.
Espanyol possible starting lineup:
Garcia; Tejero, Gomez, Cabrera, Olivan; Roca, Kral, Bauza, Romero; Cardona, Puado
Valencia possible starting lineup:
Dimitrievski; Foulquier, Tarrega, Mosquera, Vazquez; Perez, Pepelu, Guerra, Rioja; Lopez, Duro
We say: Espanyol 2-1 Valencia
Wednesday's clash will almost certainly be a close contest, with neither side wanting to lose ground on Deportivo Alaves.
Written by
Lewis Nolan