The 19-year-old midfielder has been watched by United scouts on a number of occasions this season, following five impressive first-team appearances for the Saints.
And the Old Trafford outfit are weighing up a potential summer move for the youngster, who has been tipped for great things in the game.
Reed is the latest promising talent to surface from Southampton’s youth academy, with Gareth Bale, Theo Walcott and Alex Oxlade-Chamberlain all going on to play for Real Madrid and Arsenal respectively.
Luke Shaw is another Saints play catching the eye of United manager David Moyes, and a move for both him and Reed is thought to be on the cards this summer.
Meanwhile, United skipper Nemanja Vidic is edging closer to completing his move to Inter Milan this summer.
Inter president Erick Thohir said this week: “I can’t say anything other than the deal for Vidic is 90 per cent done.”