Wayne Rooney is a doubt for the World Cup after fracturing a metatarsal bone in his right foot during Manchester United's 3-0 defeat at Chelsea.
The 20-year-old striker has been told he may be out for six weeks, exactly the amount of time until England's first game against Paraguay on 10 June.
He was carried off after an innocuous challenge by Chelsea's Paulo Ferreira.
England boss Sven-Goran Eriksson will name his provisional World Cup squad on 8 May and his definitive one by 15 May.
The Swede has previously said he would gamble on Rooney's fitness - even if there was only a small chance of him being fit for the tournament.
The England coach said in March: "If Rooney has a small problem, would you still take him? What alternative do you have?
"If you have a centre-half who might not be ready you can take another one but can you find another Rooney?"
United issued a statement on their website regarding the injury on Saturday evening.
It read: "Wayne Rooney has a fracture of the base of the fourth metatarsal on his right foot. He will be out for six weeks."
"I'd doubt very much if he makes the first World Cup game or even the second game"
"I'd doubt very much if he makes the first game or even the second game," Roberton told BBC Radio Five Live.
"I would say seven weeks. From five weeks onwards just build up the exercise and see how it goes.
"Obviously England will have machines in Germany to monitor it, to see if there is any damage being caused through exercise.
"They have to build it up from about four or five weeks and then see how it goes."
The youngster is seen as an integral part of England's bid to win the World Cup in Germany.
He broke a bone in the same foot during England's quarter-final defeat by Portugal in Euro 2004.
His absence was seen as a major factor in England's failure to progress to the semi-finals.
Rooney's position is remarkably similar to that of England captain David Beckham before the last World Cup in 2002.
Then, Beckham broke his fifth metatarsal nearly eight weeks before the start of England's World Cup campaign.
Metatarsal injuries explained