Steven Gerrard says Rooney is vital to England's chances in Germany and the Liverpool skipper is hoping his fellow Scouser is able to recover in time for the start of the World Cup.
"He's our key man and I think it's impossible to have a successful World Cup without Wayne Rooney," said Gerrard.
"Any team without Wayne is not as strong in my eyes because he is one of the world's best players now at 20.
"He can change a game at any moment - it's as simple as that. Let's keep our fingers crossed and hope he does get fit and goes to the World Cup."