The Red Devils boss is hoping a move for Everton striker Romelu Lukaku can be completed in quick time. The Belgian currently holidaying with Paul Pogba in Los Angeles, where reports suggest a medical could take place following a £75m fee being agreed.
The Portuguese has been on holiday and compassionate leave after his father, Felix, passed away last month.
The Red Devils play LA Galaxy, Real Salt Lake, Manchester City, Real Madrid and Barcelona over the course of this month.
A week on Saturday will be the first outing of United’s pre-season against the Galaxy and Mourinho will now be finalising preparation before Monday’s flight across the Atlantic.
The countdown is on to August 8 when United will take on Los Blancos in the European Super Cup in Macedonia just five days before their Premier League opener against West Ham on August 13.