Manchester United boss Sir Alex Ferguson believes only ill health would force him out of Old Trafford in the immediate future.[LNB] Ferguson famously went back on his decision to retire at the end of the 2001/02 season.[LNB]People continue to speculate on when the 68-year-old will quit and who will replace him when that time comes but Ferguson insists that after nearly 24 years in charge at United he remains as driven as ever.[LNB]"I'm confident with the kind of person I am. I don't think I will be changing at my age now. Do you think I will change?" Ferguson said in an interview to the Mail on Sunday, in which he affirmed he is not thinking of going anywhere at the moment.[LNB]"The thing I hope is that my health is OK.[LNB]"When you get to 68 years of age, you are not guaranteed anything. You hope you wake up in the morning.[LNB]"Over the last three or four years, I have lost a few scouts who have died. Great scouts, absolutely brilliant. All in their 60s.[LNB]"You are faced with that when you get to my age, where you are going to funerals of people you worked with or friends.[LNB]"So you say to yourself, 'There for the Grace of God that I am still here.'[LNB]"And that is the only thing that determines you in connection with football. You couldn't possibly do your job unless you were healthy."[LNB]It took Ferguson until his fourth season at United to win his first trophy - the 1990 FA Cup - and he did not steer them to the title for a further three years.[LNB]Manager's are rarely accorded that sort of time nowadays and the Scot believes it is this hasty, results-based culture which means it is difficult to single out a possible successor to his throne.[LNB]He added: "You can talk about the successful managers right now who might be on everyone's list. But in two years, they may not be. Or even next year.[LNB]"So it's very difficult to say who would replace me when my time came.[LNB]"Manchester United would need somebody successful for that kind of job.[LNB]"Most clubs would look for the most successful manager on the horizon. But two years ahead, they may not be successful any more.[LNB]"It is a horrible game, a results industry and, as Roberto Mancini says, you can lose three games in Italy and get sacked.[LNB]"We're getting a little bit like that ourselves.[LNB]"You think of Peter Reid, Ruud Gullit and Bobby Robson at Newcastle, sacked just into the new season.[LNB]"When you stoop to that level you have absolutely no idea how to run a football club."