Media reports in Europe have claimed a deal between United and Borussia Dortmund for Sancho is done.
The winger will arrive at United in the coming weeks and sign a five year contract.
Asked about Sancho's imminent transfer, Ferdinand told the FIVE YouTube channel: "I don't need to tell him this because he loves his football, but work hard and make sure everything you do is about being a success at Manchester United and being the best you can be.
"Don't let nothing sidetrack you. Be yourself, entertain and the end product is what you're about. Bring that to the table.
"The energy and the focus should be solely on football. Just immerse yourself in everything about the club, man."