Mourinho was going to try and secure someone in the position before the 2018/19 season, but has decided to stick with Ashley Young and Luke Shaw for the time being.
Shaw could well become the Red Devils' long term solution on the left side of defence, although that does not mean other possibilities will not be monitored over the next 12 months.
Mourinho is keen to inject his squad with youth, as shown by the recent £17.4m signing of 19-year-old Diogo Dalot, and the same will be true when looking at left sided players.
That is why previous interest in Tottenham Hotspur's Danny Rose and Alex Sandro of Juventus, both of whom are 27, has been dropped.
Instead Mourinho will keep close tabs on Fulham starlet Ryan Sessegnon - who in truth has developed into more of a winger than a full-back - and Celtic's Kieran Tierney.
With Sessegnon increasingly operating further up the pitch, if Shaw does not impress during the next campaign then Tierney could well be targeted this time next year.