Ferguson said he does not expect to continue in management past 70
Sir Alex Ferguson says he is dreading the thought of stepping down as Manchester United boss in the future.
The 67-year-old Scot believes he will find it difficult to adjust to life when he is no longer running the club he has managed for 23 years.
Ferguson told L'Equipe: "I am in the penalty shoot-out of my career but I'm scared about thinking about retirement.
"I have been on the train for so long that when I get off it, I am scared my body will shut down."
Ferguson, who won the European Cup in 1999, almost retired in 2002 but changed his mind and went on to win the Champions League again last year and is on course for a quintuple of trophies this season.
In November, he celebrated a half-century in football having won 10 Premier League titles, five FA Cups, the League Cup twice, and the Champions League twice.
Ferguson, who recently said he does not expect to continue in management past the age of 70, added: "Three reasons are going to make me say 'quit' - if my health deteriorates, if I no longer enjoy working, if I no longer have the strength to rise to the challenges.
"Each summer I ask myself these three questions. I go to see my doctor, to start off with. My age has put me on alert since I had a pacemaker set up four or five years ago.
"My doctor says, 'Boss, you are 67, your back is going to get worse and worse. There are mornings when getting up is not going to be easy'. These are the penalties."
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