Nemanja Matic insists Mason Greenwood cannot be expected to lead Manchester United's title charge.
The 17-year-old will likely feature in Ole Gunnar Solskjaer's side this season after a strong preseason showing.
But United veteran Matic has moved to lower expectations of the talented forward.
He said: "Mason Greenwood, great potential. United have a project and know what they want with players of the future. But you need to give them time because, at 17, you cannot play the same like you are 26 or 27.
"Football always wants results but the fans need to be patient so they can improve. In the future I am sure these players will take United back where they belong."
