By Nathan Ridley Manchester United have made a formal approach for Southampton director of football Jason Wilcox \- but face a significant hurdle. United are keen to make Wilcox, 52, the latest addition to their new-look footballing department ran by co-owner Sir Jim Ratcliffe and his INEOS colleagues. Ratcliffe, who recently purchased a 27.7 per cent stake at Old Trafford, has already helped hire Omar Berrada as the club’s new CEO, while Newcastle sporting director Dan Ashworth remains in talks to join the Red Devils. Multiple reports say that United want to make Wilcox an integral part of th…