Manchester United have been keen to strengthen their left-back options with Ashley Young playing much of the season in the unfamiliar role.
Luke Shaw’s future at Old Trafford remains uncertain due to his fitness concerns.
And it was reported last month that United were going to enter the race with Chelsea to sign Sandro from Juventus.
But the Italian club are unwilling to let their star defender go on the cheap.
They have reportedly asked for close to £62million and the Daily Record claim that United are not willing to pay that much for a full-back.
It is said Mourinho will instead turn his focus on Celtic’s Kieran Tierney and Fulham teenager Ryan Sessegnon.
The Portuguese coach has been watching intently of the performances of both left-backs and has been impressed by what he has seen.
Tierney has been an ever-present in Brendan Rodgers’ side this season and has attracted plenty of admirers for his displays in Europe.
Meanwhile Sessegnon, 17, has been linked with a number of clubs in recent months with his scoring ability a main attraction.
Mourinho is said to favour a more experienced player to bed into his United side with Tierney the preferred option due to his Champions League experience.