Groin injury scuppers Rooney

Groin injury scuppers Rooney - Yahoo! Sport UK
Wayne Rooney has been denied the chance to be part of Steve McClaren's first England squad through injury.The Manchester United star has not been included in the 25-strong party to face Greece in next Wednesday's friendly international at Old Trafford because of a groin injury.
How serious is this? Giggs-before-Wales, or is it a real injury?