Emery's side currently sit in 10th place ahead of their weekend opponents on goal difference, but they are only six points off a top-seven berth which could yet earn them a place in Europe.
The former Valencia boss has urged his players to leave nothing to chance by ending their recent sequence of three games without a win and finishing the season on a high.
He said: "It is an important match for the standings because we still have to think about seventh place and it is something we can achieve.
"We are getting optimistic and expectations are raised. We need back-to-back wins to get towards the final space. We have to make up six points, but we have to believe it is possible."
Espanyol will harbour similar ambitions even if their chances took a hit last weekend when their run of six games unbeaten was ended by a 1-0 home defeat to Granada.
That result left the Barcelona-based side in 11th spot, level on 43 points with Sevilla.
Coach Javier Aguirre said: "This is a long race and there are still 15 points to play for. We did not play as well as usual last week, but we are good self-critics and this will help us grow."
Espanyol welcome back defenders Diego Colotto and Raul Rodriguez after suspension, but Felipe Mattioni, Cristian Alvarez and Simao Sabrosa are all injury absentees.
For Sevilla, midfielder Ivan Rakitic is a doubt after suffering an ankle injury in training while winger Jose Antonio Reyes is also unlikely to be fit after picking up an ankle injury of his own last weekend.