The 21 year-old is hot property this month and has already been linked with moves to Arsenal and Liverpool.
The Red Devils had hoped to hijack the deal but according to reports, saw their efforts rejected by Palermo.
Club chief Maurizio Zamparini has confirmed that United had “been in contact” but is not willing to let the striker go for any less than £31m.
It hasn’t been revealed how much United had offered for the striker, but it was under the asking price.
By Phil Wellbrook