The Scottish Knight has always been assumed to control his own destiny.
David Gill (presumably with the approval of the Glazers) has implied that Sir Alex would decide when to retire and part of that would take account of his possible successors.
But United had already started to prepare for Sir Alex's departure in 2010. So why is the end of this season the right time to go and who should succeed him?
It has seemed clear for some time that while he will have a significant say about his successor, the final decision will be taken by a small "appointments committee." While making his own recommendations, Sir Alex is not likely to be on that committee.
It is fairly certain that David Gill and Sir Bobby Charlton will be.
Manchester United would have no shortage of candidates, despite some probably discounting themselves because of the scale of the challenge of succeeding the greatest football manager of the modern era, possibly even all-time.
The financial package and duration of the contract will not be an issue. With players on more than £10 million a year, why would United skimp on the terms for the right man?
Sir Alex will have presided over almost 27 years of unparalleled success by next May, during which he has sculpted the Premier League and rewritten English football history. He has also moulded several footballing legends, some of whom are counted amongst the greatest players ever.
So let's be clear.
This article is not about saying it is time for Sir Alex to go, nor is it a knee-jerk to recent results or prospects.
It simply recognises that one day he will retire, reads the runes about when that might be and discusses possible reasons why the end of this season could be the time.