Pogba's future at Old Trafford has come under scrutiny on a number of occasions in recent months amid reports that he has fallen out with manager Jose Mourinho.
Former club Juventus are understood to be interested in re-signing the World Cup winner, but Barcelona have also been heavily linked with a move and are thought to have made him their number one priority this season.
The Mirror reports that Barca sent scouts to watch Pogba during his man-of-the-match performance against Young Boys in the Champions League on Tuesday night and now plan to keep close tabs on him for the remainder of the campaign.
Barca are reportedly confident that Pogba will be eager to swap Old Trafford for Camp Nou and have already prepared an offer worth in excess of £100m.
The 25-year-old has scored four goals in six games so far this season, putting him on course for the best goalscoring campaign of his career.