Ferguson knew Redknapp had a difficult relationship with Spurs chairman Daniel Levy.
He told the Daily Mail: "When England turned to Roy Hodgson I thought Harry would have a problem. I don't think his relationship with Daniel Levy has been that good, ever since he arrived there. That was maybe an opportunity for Levy.
"There was a lot of blame put on the talk of the England job. The press were all for Harry, that was a handicap to him really in terms of his relationship with Levy so I wasn't surprised at that."