Boss Sir Alex Ferguson told Sky Sports News: "I doubt we'll get Rooney fit for the start of the season with the virus he's had.

"It's a virus he picked up in Nigeria and it's not a nice one, but quite a few have had it.

"It's such a bad virus and he's got to be training to be fit."

Ferguson confirmed that it was not malaria, against which the entire squad had been treated before the trip.