One step away from a potential World Cup final, Argentina is hoping for Angel Di Maria to recover from a thigh injury in time for Wednesday's semifinal clash against Netherlands.
The Real Madrid winger strained the back of his right thigh in Argentina's 1-0 win over Belgium, and was to undergo medical tests on Sunday to discover the extent of the injury.
Losing Di Maria would be a big blow for Argentina as it prepares for its first World Cup semifinal since 1990. Besides Lionel Messi, he's been Argentina's most influential player in Brazil.
Di Maria scored the extra-time winner against Switzerland in the second round and set up Gonzalo Higuain's winning goal in the first half against Belgium on Saturday.
"He's a key player in this project," Higuain said of Di Maria. "We hope that he will be ready as soon as possible because we know what he does for the team."
Coach Alejandro Sabella called Di Maria "vital" to Argentina, which is already missing striker Sergio Aguero due to injury.
Sabella also praised Messi's performance against Belgium, even though he didn't score. The four-time world player of the year started the move that resulted in Higuain's goal, pirouetting past two Belgium players before giving the ball to Di Maria whose pass deflected off a defender into Higuain's path.
"Messi, I feel that he played a wonderful match because it is not only scoring goals," Sabella said. "It is bringing together three opponents and to see if you can give the ball to a teammate to move forward in the pitch. Every move he makes is a sign of hope for us and it endangers the opponent."
The last time Argentina reached the semifinal stage in the World Cup was 24 years ago in Italy, when it made it to the final but lost 1-0 to West Germany.
Sabella said being among the final four was the "minimum" that Argentina expected out of this World Cup after being eliminated in the quarterfinals in two consecutive tournaments.
With Messi - a four-time world player of the year- at the prime of his career, the country was demanding more in Brazil. But despite a relatively easy draw, Argentina scraped by with narrow wins in the group stage and needed extra time to beat Switzerland in the second round.
Sabella made two key changes to the lineup against Belgium, fielding Manchester City defender Martin Demichelis for the first time in Brazil, and having Lucas Biglia replace Fernando Gago in the midfield.
"You always hope to play," Demichelis said. "I was showing a lot of heart in practice and tried to get to the place where I would get called up."
The moves bolstered Argentina's defense, with Biglia and Javier Mascherano dropping back to help protect the early lead.
With left back Marcos Rojo returning from suspension Argentina's defense should be in even better shape for the semifinal. However, the attack is bound to suffer if Di Maria cannot recover in time.