4. Christian Eriksen
Current club: Ajax Denmark midfielder Eriksen was instrumental in Ajax's Eredivisie title win last year, with an impressive 8 goals and 21 assists for the season, and the 20-year-old would be a considerable boost to United's midfield options, alongside new man Shinji Kagawa. He would also be affordable without breaking the bank, thanks to Ajax's well-publicised financial problems that saw star defender Jan Vertonghen head to Spurs for just £10m earlier this summer. Eriksen would be a strong contender to replace Michael Carrick; able to play either in a deeper role or as a playmaker, where he could unlock play and bring Wayne Rooney and the wider players into the game further up the pitch rather than Rooney having to persistently drop deep to receive the ball. The good news for United is that Eriksen is said to want to move to Old Trafford, expressing United and Barcelona as the two teams he would consider joining from Ajax after Sir Alex expressed his admiration for the midfielder in the wake of two impressive displays against his own side in the Europa League. Sir Alex may well look to a more defensively minded player first, but Eriksen's stats don't lie, and the Eredivisie has produced a lot of talents in recent years who have made the step up to the Premier League well and seamlessly integrated into the fast pace of the division. £20m for more than 20 assists and 8 goals would represent a fantastic deal considering how much Liverpool paid for Charlie Adam and Jordan Henderson recently.