Chelsea's Daniel Sturridge is being treated for viral meningitis and may be a doubt for the Olympics.
Sturridge, who was named in Stuart Pearce's 18-man squad on Monday, is undergoing further tests to determine the full extent of his illness.
It is believed the 22-year-old began to show symptoms of the illness last week and Chelsea's medical team as well as the Football Association's doctors have assessed Sturridge's condition.
The squad are expected to meet up this weekend, but Pearce could delay that to find out if Sturridge will be able to feature at the games.
If Sturridge is ruled out of the Olympics tournament it will be a major blow for the forward after he missed out on Roy Hodgson's squad for Euro 2012.
Pearce has been expected to use Sturridge in his starting XI and if he is forced to withdraw from the squad it could pave the way for the likes of Crystal Palace forward Wilfried Zaha, who is on Pearce's standby list, to be drafted in.
Team GB kick-off their bid for Olympic gold against Senegal at Old Trafford on July 26.