#1 Daley Blind

Daley Blind was a sought-after man after his brilliant displays for the Netherlands in the 2014 World Cup. He was pivotal and helped them reach the semi-finals. United beat Liverpool to his signing and it was supposed to earmark a new era at the club with an influx of new players and also a new manager.
But the Dutch have fallen and so has Blind. Though he is the captain of the national side, his best games for United have been few and far between. Lauded for his versatility and intelligence, Blind was considered to be adept at playing left-back, centre-back and defensive midfield.
But to play in a back four, a player has to be quick and strong, qualities which are not associated with Blind. He may get away with it against smaller teams but in games against title-contenders, he is a definite liability. This season, he has been woefully out of form and has only featured in 19 games.
He was offered to Roma in January, so clearly the United hierarchy are unimpressed with him. Mourinho seems reluctant to play him in his best position of a defensive midfielder and if he intends to continue with this stance, then it is best that he sell Blind this summer.