Chelsea manager Roberto Di Matteo has confirmed striker Daniel Sturridge has viral meningitis.
At a press briefing at Chelsea's training ground he said the striker was taken ill over the weekend.
Chelsea are receiving hourly updates on the striker's health and say the club's doctors have been with him since he was taken ill.
"What matters is he gets well soon", said Di Matteo, who said he hoped he would still be able to play in Team GB's Olympic football team.
"We will be monitoring him on a daily basis but the fact that he is feeling better is very positive, I'm optimistic that he will recover and will be able to join the team", Di Matteo said. Sturridge remains in hospital.