#3 Saúl Ñiguez

The product of Atlético Madrid's youth academy, Saúl Ñiguez has emerged as an important midfield general for Diego Simeone's side in recent years. A versatile midfielder known for his work rate and intelligence, Saul has a lot of playing experience, appearing over 250 times for Atlético Madrid, and he is only 25 years old.
Besides playing as a central midfielder, he can also be played as a defensive midfielder and a winger. It's no wonder that the Spaniard is known for his versatility. He is also one of Spain National Football Team's first choice midfielders, and hence, also has a lot of experience in international football.
As United lost a brilliant midfielder and a leader in Ander Herrera in the summer, the recruitment of Ñiguez would make up for it, even if he would cost a lot. There is no doubt that he would be a very good signing for United and would serve the club for years to come.