The Madrid side currently sit in 12th position but with only five points separating 19th from 10th, Valera is also wary that they cannot get complacent after a good run in December.
He told the club's website: "If we can put together another three or four good results then we will be in a position to fight for something more, to be in the top eight or 10. However we also realise that we can't relax and the primary objective is still to move away from the bottom.
"Beating Athletic would help us open up that gap to the teams below us and ease the pressure so we can start to play our best football."
Getafe will also be boosted be the return of a number of key players, with Valera returning from suspension along with Michel and Diego Castro while Pedro Leon could make his comeback after three months out with a knee injury.
Athletic are hopeful of having talisman Fernando Llorente back to lead the line, however it is more likely Marcelo Bielsa will keep the Spain international on the bench from the start and ease him back into competitive action as the club continue to look for a solution to his persistent knee problem.
The Basque side have struggled for goals in Llorente's absence but midfielder Ander Herrera still believes Sunday's clash will be an attractive one to watch.
He told Efe: "We are travelling again and it will be a difficult game because neither team know how to play any other way than to try and win.
"Ever since they came up to La Liga, Getafe have maintained a certain style of play and they look after the ball. However, I believe we have the qualities to win the game."
Athletic will also have Javi Martinez available after his red card against Real Zaragoza was overturned on appeal, while captain Andoni Iraola returns from suspension.