Valencia striker David Villa may miss Sunday's match at champions Barcelona after landing awkwardly and hurting his shoulder in Thursday's 1-1 Europa League last-16 first-leg draw at home to Werder Bremen.
"It's a very painful injury which is being treated with analgesics and anti-inflammatories," the club said on their website on Friday. "The player will be a doubt for Sunday's match against Barcelona right up until the last minute."
Valencia's pacy attack will pose a threat with or without Villa, the second-highest scorer in La Liga this season with 17 goals, Barca defender Rafael Marquez told a news conference on Friday.
"Villa is a special footballer but with or without him it won't be easy," the Mexican said.
Barca, level on 62 points with leaders Real Madrid but behind on goal difference, will be without Zlatan Ibrahimovic after the Spanish football federation (RFEF) rejected their appeal against the Swedish striker's red card last weekend.
Coach Pep Guardiola was also sent off during the 2-2 draw at Almeria will have to watch from the stands as the RFEF also turned down Barca's appeal against his dismissal.
Real Madrid's elimination from the Champions League on Wednesday will make it harder for Barca to retain their La Liga title, according to defender Gerard Pique.
"Now they will be focused only on the league and that means they will lose very few points," Spain international Pique said in an interview with Barca TV. "Things will be more difficult."
Real director general Jorge Valdano has reiterated his backing for coach Manuel Pellegrini after the nine-times European champions failed to reach the last eight of the Champions League for a sixth straight season.
"The plan at the moment is that (Pellegrini) remains in his job to give some continuity to the project," Valdano told Spanish radio on Thursday. "At the end of the season we'll see how much damage has been done to all of us and we'll make a final decision."
Pellegrini's side take on struggling Real Valladolid in Sunday's late kick-off. Valladolid coach Onesimo Sanchez said he would not settle for a draw and his players would fight for what would be only a fourth win this term.
"In our situation, and in front of our own fans, we have to go out there and scrap and win," he said on the club's website. "It will be key for us to work together to win back the ball and try to give some structure to our play."
Real defender Raul Albiol, who joined from Valencia as part of an unprecedented 250 million-euro spending spree last summer, said the players had to pick themselves up and take their bid to dethrone Barca forward.
"We are into the final straight in the league and we can't take our foot off the gas," the Spain international told a news conference. "We have no choice but to carry on and focus on the fact that the project has only just begun."
