Liverpool striker Fernando Torres is a major doubt for the start of the new season after suffering a grade one rupture to a thigh muscle.
The Spain international ended Sunday's World Cup final victory over the Netherlands in South Africa with a problem after pulling up sharply in extra-time.
It was initially thought that the injury-plagued frontman had suffered a groin injury which would keep him sidelined for around three weeks.
However, scans conducted in Madrid on Tuesday have revealed "a grade one muscle fibre rupture in the left thigh", according to the Spanish Football Federation.
Torres finished last season on the Anfield treatment table following a second operation to cure a long-running knee injury.
He still managed to score 22 times in 39 appearances for the Reds, but looked out-of-form during a goalless World Cup campaign.
The news comes as a blow to new manager Roy Hodgson, who was told on Tuesday by the club's new head of medicine and sports science, Dr Peter Brukner, that the injury did not look too serious.
"We've been in touch with the Spanish medical team and they don't think it's too serious. It's an adductor muscle injury but they've not had a chance to assess it today," he said.
"Fernando will have a proper assessment and probably a scan tomorrow and some of the Liverpool medical staff will go to Madrid later in the week to fully assess the injury and organise his rehab. At this stage we don't think it's too serious."