#3 Ander Herrera
Ander Herrera was one of the first signings of Louis Van Gaal at Manchester United. Having been a good performer at Athletic Bilbao, Herrera was tipped to emulate Paul Scholes. He was even considered Iniesta's successor with the Spanish national team.
However, the Spaniard has failed to impress the United fans with his performances in recent times. As a matter of fact, Herrera was one of the best players at Manchester United until Mourinho signed Matic last year.
Herrera's opportunities reduced, and hence his form too. He was ignored by the Spanish national team for the last World Cup, and he has had almost no game time this season in the Premier League. With Bilbao still interested in their former player, Manchester United may be tempted to sell him to make way for a big name signing.