Barcelona midfielder Xavi Hernandez is playing with a muscle injury that could keep him out of the World Cup.
Xavi said after Saturday's 4-1 win at Villarreal he was playing with a small tear just above his calf.
"The truth is I'm carrying a number of aches but the team has a lot on the line and I want to be here," said Xavi after scoring one goal and assisting on two others. "There's only three games left so I have to push and if I'm pushing it's because I think I'm OK.
"Also, my game is not an explosive one."
Xavi said he would be fit to play in the June 11-July 11 tournament in South Africa, but coach Pep Guardiola wasn't so sure.
"Xavi's playing with an injury that could see him miss out on the World Cup," Guardiola said. "He's an example to all of us. He's made this extra effort because he knows he can't leave us on our own now. Fortunately (the injury) hasn't relapsed."
Xavi was named Spain's top player during its European championship winning run two years ago.
Spain opens Group H play against Switzerland on June 16 before also facing Honduras and Chile.
Barcelona leads Real Madrid by four points in the Spanish League, although Madrid has a game in hand.