Manchester United have a new head coach and right now he will be getting to grips with his new role in Carrington. However, the 39-year-old Portuguese coach has already made one big decision at Manchester United. Ruben Amorim has only been in Manchester a few days and yet has already got fans believing once again. The former Sporting Lisbon boss was pictured with Leny Yoro and Kobbie Mainoo on Tuesday, which got fans carried away with excitement over how he would use the youngsters. One man who wouldn’t have been happy to see Amorim’s arrival however is Ruud van Nistelrooy, as the Dutchman’s s…