Steven Gerrard has revealed he is not certain to be fit enough to play in England's World Cup opener against Paraguay on Saturday.
The Liverpool midfielder sat out training on Wednesday after a knock to the hip which resulted in him suffering back problems, but resumed working with the rest of the squad on Thursday morning.
The signs are positive that he will not suffer the heartbreak of missing a second consecutive World Cup finals because of injury but he fears the Group B clash in Frankfurt could come too soon for him.
"It is not a back problem. I got a knock on my hip which made my back go into spasms," said Gerrard.
"The good thing is it is improving all the time. I have got a good chance of playing on Saturday, but I need to keep working on it from now until Saturday.
"What is a good chance? As we speak now, I am probably 50-50 to play - but if it keeps improving as it has done over the last 24 hours, then I'll be there.
"I don't know how it is going to respond but it has improved a lot over the last 24 hours. If it keeps going in that direction, I am confident I will be ready for Saturday."