The Red Devils have added Victor Lindelof, Romelu Lukaku and Nemanja Matic to their squad as they prepare for a title tilt.
The Independent claim Mourinho wants two new full-backs and another midfielder before the transfer window slams shut.
The report says tensions have eased between the Special One and United chiefs after the signing of Matic.
Mourinho still feels deals should have been concluded before his side went to the USA on their pre-season tour.
And he is particularly frustrated with the pursuit of Ivan Perisic from Inter Milan.
United remain confident they will get a deal over the line for the Croatia international but Anthony Martial will not be going the other way.
Mourinho is keen to sign two new full-backs and has been offered Paris St-Germain star Serge Aurier.
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However, on the left side of his defence, Luke Shaw is now United’s first choice with the Portuguese impressed with his attitude and form in pre-season.
Fabinho has also been linked with a move to Old Trafford.
United start their Premier League campaign against West Ham on Sunday, August 13.
Before that they take on Champions League winners Real Madrid in the European Super Cup next Tuesday.
