"I am not so sure about Wayne," said Ferguson. "Maybe I will have him as a substitute on Sunday. But he will certainly be fit for the Champions League final."
Ferguson delivered better news on the fitness of Nemanja Vidic, who suffered concussion at Stamford Bridge, as well as a nasty cut to his lip.
The tough-tackling Serbian defender has been cleared by the United medics to face Steve Bruce's men, with Ferguson confirming Vidic will play providing he comes through the remaining training sessions unscathed.
"We are very hopeful of Nemanja being fit," said the Scot. "He is clear medically, so the next two training sessions will be very important.
"But he is much better and hopefully I can get him right for Sunday."