Osasuna defender Ruben Martinez admits the team are worried about their chances of avoiding relegation due to the good form of other sides fighting for Primera Division survival.
Fellow strugglers Zaragoza, Celta Vigo and Granada all achieved victories last weekend, while Deportivo La Coruna - bottom of the table a month ago - have taken 14 points from their last six matches.
Osasuna, meanwhile, are only three points clear of the relegation zone and have taken just five points from their previous six matches.
Ruben told a press conference: ``More than nerves, there is tension. We know the situation we are in. Any of the five teams below could swap places with us and we are aware we are on a poor run.''
The Navarrans travel to Valencia and Ruben stressed the team must not return home with nothing.
``We need to pick up points, because the other teams at the bottom will,'' he said.
``A month and a half ago we thought 37 points would be enough to stay up but, like every other year, it seems that won't be enough.''
Ruben acknowledged that the Mestalla was a less than ideal place to go, and urged his team to ``at least put on a brave display to encourage us for the rest of the season``.
``We know how difficult the game will be,'' he added. ``The Mestalla is a daunting stadium, but you have to play in all of them.''
Valencia go into the game off the back of their crushing 4-2 defeat to Real Sociedad last Sunday, which put them five points adrift of the Basques in the hunt for the final Champions League spot.
Defender Ricardo Costa has refused to throw in the towel, and was positive about his team's chances of catching up with Philippe Montanier's side.
He said: ``The important thing now is to pool together our strength and fight. Every game is a final for us and we have to keep fighting until the last moment.
``The Champions League is very important for the club, the players and the fans. We have to try and get all 15 points (from their final five games) because there are always surprises in football. We know that we should win the next five games and we hope that La Real drop points.''
Veteran midfielder David Albelda will miss out due to suspension, while centre-back Adil Rami is Valencia's biggest injury concern.