Ed Woodward has missed his first pre-season tour since taking over as Manchester United chief six years ago in a bid to finalise transfer deals before next month's deadline.
United remain locked in negotiations with Leicester City over England defender Harry Maguire, and are also expected to make a fresh offer for Newcastle midfielder Sean Longstaff.
Woodward was expected to join the tour of Perth, Singapore and Shanghai - which ends with Thursday's game against Tottenham at the Hongkou Stadium - but has remained in England to work on transfers.
It is the first time he has missed the trip since taking the reins from David Gill in 2013 when United's former chief executive left Old Trafford along with Sir Alex Ferguson.
An earlier transfer deadline of August 8 this year means Premier League clubs have three weeks less than usual to get deals over the line, although players can leave for foreign clubs after that date.
Woodward, who had a brief family holiday in Marbella, has just over a fortnight to deliver the signings manager Ole Gunnar Solskjaer wants after spending £67million on Aaron Wan-Bissaka and Dan James so far this summer.
Leicester are demanding in excess of £80m for Maguire, who is also wanted by Manchester City, but United have failed to meet the valuation after making two bids. They have other options in mind, notably Napoli's Kalidou Koulibaly.