United travelled to Benfica during the week and took a step towards qualifying for the Champions League knockout stages, but it also gave Mourinho the opportunity to take a look at one of the Portuguese side's promising youngsters.
Despite their defeat, left-back Alex Grimaldo, formerly of Barcelona, impressed for Benfica during the game at the Estadio de Luz.
According to reports in Portugal, the performance from the 22-year-old Spaniard caught the eye of the United boss.
'Record' reported that Mourinho has given the go-ahead for the Red Devils to pursue a deal for the defender as he looks to strengthen in the left-back position.
Selon @Record_Portugal ManUnited suit #Grimaldo (que City avait aussi dans le viseur) #Benfica pic.twitter.com/73NrygolQy
— Nicolas Vilas (@nicolas_vilas) October 21, 2017
They also report that United will send scouts to watch Grimaldo's next games closely.
Left-back has been somewhat of a problem position for Mourinho so far, with Ashley Young, Matteo Darmian and Daley Blind all having filled in there.
The rotation of those three players has been necessary for United with Marcos Rojo a long-term absentee through injury and ongoing doubts by Mourinho over Luke Shaw's form and fitness.