(CNN) -- Spain striker Fernando Torres may not be fit for the start of the World Cup, according to his English club Liverpool.
The forward scored 18 goals in 22 games in the Premier League before his season was cut short by a knee injury.
Torres had surgery to repair a torn cartilage in April and is now racing to be fit for Spain's opening game at the finals with Switzerland on June 16.
Peter Brukner, Head of Sports Medicine and Sports Science at Liverpool, says the 26-year-old may not have recovered in time to launch his country's charge for the trophy.
He told Liverpool's official Web site: "You can't be absolutely certain of anything but at this stage, if he continues to progress the way he is, he should be fit to play at some stage during the World Cup.
"Whether he'll be fit for the first game or not is uncertain. We're anxious not to hurry him along too much because we want the long-term benefit, but we're aware he's got the short-term goal of playing in the World Cup."
Meanwhile, Germany coach Joachim Loew has been dealt a double blow ahead of the World Cup after goalkeeper Rene Adler and midfielder Simon Rolfes were ruled out of the tournament through injury.
Adler has been told he needs surgery on a rib injury, aggravated while playing for his club Bayer Leverkusen during their weekend German Bundesliga draw with Hertha Berlin.
He has been the country's number one since Robert Enke committed suicide in November 2009, and has nine caps to his name.
"This was the hardest decision of my life," Adler told the German Football Association's Web site. "The pain is so great that I would not have been able to perform at my best over the longer term both in training and during matches.
"In such a long and intensive tournament, that is unacceptable. You need players who are totally fit."
Rolfes, who also plays for Leverkusen, has been out of action since an operation on a knee injury back in January and will not be adding to his 21 caps at the finals in South Africa.
He said: "I am very pleased with the healing process but it is now definitively clear that the World Cup finals for me make no sense.
"My plan is now to look to start the new Bundesliga season fully fit. Missing out on the World Cup is not easy. It only remains for me now to wish the team every success in South Africa."
Meanwhile, striker Ruud van Nistelrooy has been left out of Holland's provisional World Cup squad, but coach Bert Van Marwijk says it doesn't necessarily spell the end of his World Cup dream.
The 33-year-old former Manchester United and Real Madrid forward is currently playing for Hamburg in the Bundesliga.
"As for Ruud, I'm giving myself until May 11 to decide," Van Marwijk was quoted as saying in a story on FIFA's Web site. "I'm leaving him until that date to convince me that he is sufficiently in shape to take part in the World Cup."