Saints left-back Luke Shaw is due to have a medical at Manchester United ahead of a proposed transfer to Old Trafford.
The 18-year-old defender is expected to travel to the north west shortly, as he looks to complete a switch for around £30m.
Talks between Saints and United are believed to have taken place in the past few days, and an agreement now looks close to being finalised.
As revealed by the Daily Echo earlier this month, Shaw informed the club that he wished to leave St Mary's this summer.
United initially submitted an offer worth a potential £27m - although with far less guaranteed money than that headline figure - following the conclusion of the Premier League season, but negotiations were put on hold until a new manager was in place at St Mary's and the World Cup was over.