French international Schneiderlin, who has been ever present in the Southampton midfield since he moved from Strasbourg as an 18 year old, has been angling for a move since his infamous outburst on social media last season.
However, Schneiderlin put in some impressive performances in Saints' record-breaking season in England's top flight - despite being refused his move away from the South Coast.
Said performances have obviously impressed United coach Louis van Gaal, who has made an expensive effort to boost an ailing United midfield having a rumoured deal in place to bring in Bayern Munich captain Bastien Schweinsteiger to Old Trafford.
Southampton boss Ronald Koeman and Les Reed - Saints' Head of Football Development - had said Schneiderlin will not be sold for anything less than the club's £25million valuation of the player. United reportedly put in a bid of £20million a few weeks ago, which was promptly rejected.
Now, it would appear United have agreed to stump up the extra £5million cash for the Frenchman's services.
Southampton have already sold Nathaniel Clyne and lost out to Tottenham in trying to sign former loan star Toby Alderweireld. This is the latest, yet expected, transfer blow to Saints this summer.
Saints fans will be hoping a suitable replacement is already in the works. Dutch International midfielder Jordy Clasie is being heavily linked to play under Koeman's management again after they worked so well at Feyenoord in Holland's Eredivisie.