The Argentine has been an on/off target for the Red Devils for the majority of the past few years and was linked with a switch to, Old Trafford prior to the last transfer deadline.
However, the Manchester giants didn’t match the £25m release clause in his Benfica contract, but reports claim that they have not been deterred, with the South American being scouted ahead of next month.
It’s understood that representatives from Old Trafford were in attendance for Monday’s match between the Lisbon giants and Braga to watch Gaitan.
Benfica are reluctant to sell their man, but the player himself, at 27-years-of-age, may consider a big move too good to refuse at this stage of his career.
Negotiations between the two clubs are expected to be kicked off before the end of the week.