Manchester United have a number of young players coming through, and Old Trafford legend Wayne Rooney has been particularly impressed with one of them. Kobbie Mainoo is only 18 now and is just starting his career. But, the midfielder has already established himself as an important player in the Manchester United first team. And, Wayne Rooney has been hugely impressed. The United legend has said that Mainoo is an incredible player and has a bright future. The TNT Sports pundit has compared Mainoo, who is in line for a new contract with United, to Bastian Schweinsteiger. Schweinsteiger did not h…