Ferdinand retired from international football last season.
He told the Manchester Evening News: "I know that retiring from international football was far better for me and for Man United. I know it is a positive for my game and for the club. Believe me it wasn't a decision I took lightly. People assume it was a rash decision but they couldn't be any more wrong.
"It is never easy having to decide to give up something you love and I did love playing for my country. I was so proud. I thought about playing for England ever since I was a young kid. I thought about pulling on that white shirt even before I thought about playing for any club. It was my boyhood ambition."