#2 Aaron Wan-Bissaka

The Crystal Palace star is arguably the most wanted right-back in the Premier League right now. He has undoubtedly been essential for Roy Hodgson side's in their Premier League survival due to his outstanding defending prowess.
He has amassed an average of 3.9 tackles and 2.2 interceptions this season and would strengthen United's defense significantly. He can easily find space for his team due to his equally outstanding dribbling stats (1.8 dribbles completed per game).
However, the Englishman would still need to improve his passing accuracy to be a world-class full-back. He could trouble United's counter-attack build-up as he has missed more than 20 percent of his deliveries on average this season.
Nevertheless, he is just 21 years old and has a load of rooms for improvements. He would be a worthy investment for United due to the club's recent defensive issues.