The People says the Â£23.5million buy-out clause in Fellaini's Everton Âcontract expires on August 14.
Fellaini still has three years remaining on his Everton deal and the Goodison Park club will demand more than Â£30m for the 25-year-old once his clause has expired.
It was former Everton boss David Moyes, now in charge at United, who insisted on the deadline when the buy-out clause was negotiated into ÂFellaini's 2011 contract Âextension. Having lost Joleon Lescott to Manchester City at the end of the 2009 summer transfer window, Moyes wanted to make sure Everton would not be left in a similar position and would have time to replace ÂFellaini.
A source close to Fellaini said: "Marouane respects the terms of the agreement he signed with Everton and has good moral standards. It is up to the club how they act."