He wrote in the Daily Mail: "Change is difficult to work through and it permeates the entire organisation. But Manchester United is a robust business. If anyone can get through change it's that organisation. David Moyes is a great character and Bill Kenwright summed it up when he said he has done remarkably well. His passion and commitment makes him a candidate for every opening.
"I think the days of giving managers time in the manner Sir Alex had may have come and gone. The ambitions of owners are very different to what they were once upon a time.
"We all know the story about Sir Alex and the FA Cup tie against Nottingham Forest when they were moments from getting knocked out before Mark Robins scored and kept him in the job. I think it will be a long, long time, if ever, we see a manager at a club for 27 years again."