Valladolid occupy the third of the relegation places and are three points adrift of the current safety benchmark.
After just six points from their last 10 games, speculation is building that another defeat could put coach Martinez's job under threat.
He told the club's website: "The only objective is to win this Saturday against Villarreal, we can not set ourselves any further goals.
"They are a dangerous opponent, they are very disciplined tactically and play at a high tempo.
"I am convinced it will be okay but it is true we must play better."
Los Pucelas will hope the signing of Serbian centre-back Stefan Mitrovic on loan from Benfica can shore up a troubled back line which has conceded eight goals in the last two games.
Villarreal, by contrast, have the third-meanest defence in the Primera Division, alongside Real Madrid on 21 goals conceded. Only leading pair Barcelona and Atletico Madrid can better that record.
Goalkeeper Sergio Asenjo hopes that can be the platform to a surprising finish in the table.
The Yellow Submarine go into the game on a three-match winning streak and in fifth place, two points behind fourth-placed Athletic Bilbao.
Asenjo said: "The Primera is of a very high standard and it is very difficult to keep a clean sheet, but if we continue with this work and commitment we can finish the season much better than we expected."
The 24-year-old, on loan from Atletico Madrid, will face the club where he started his career and said: "That makes it a game full of emotions.
"I grew as a person and as a player there, so I have a special affection for them, but I will leave everything on the field to defend my club and fight for the three points."
Villarreal are without Cani (knee), Pablo Iniguez (hamstring) and Aleksandar Pantic (thigh).
Valladolid's Marc Valiente failed a fitness test on a sprained ankle suffered in the 4-2 defeat to Bilbao and will join fellow defender Alcatraz, midfielder Lluis Sastre and forward Humberto Osorio on the sidelines.