Willian
Manchester United do not have a player in the squad who is an out and out right winger. Willian can be the ideal solution to that as he is a brilliant player on the right flank for Chelsea and Brazil.
The Brazilian has been linked with a move to Old Trafford for a year now. He is reportedly unhappy at Chelsea because of Antonio Conte and the Red Devils need to take full advantage of it.
Jose Gimenez
Chris Smalling and Phil Jones are not the kinds of defenders who are going to win you crucial games. Rather, they make the blunders that lead to the opponents taking the game away from Manchester United.
Eric Bailly is the only reliable defender in the squad right now. Victor Lindelof is better than Smalling and Jones but is still getting the hang of playing for a European giant.
Alex Sandro
Luke Shaw, Matteo Darmian and Daley Blind have been so bad that Jose Mourinho has been playing Ashley Young as a left-back for a long time now. This cannot continue for the Red Devils if they want to be challenging for the title in the Premier League or Champions League.
They need a world class left back and Alex Sandro can be the one for them. He was linked with a move to Chelsea last summer and then with Manchester United in January. However, he stayed put at Juventus as they were not willing to sell him.