Sir Alex Ferguson has revealed he made his mind up to retire as Manchester United manager in December.
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Ferguson announced on Wednesday morning that he had decided to quit at the end of this season after nearly 27 years in charge at Old Trafford.
His final game at Old Trafford was Sunday's 2-1 win over Swansea, which was followed by his 13th Premier League trophy presentation.
There have been plenty of questions asked about when Ferguson made up his mind to go, with some wondering whether he had been eased out given last week's programme notes, in which he insisted he was staying, or whether it had something to do with his health.
Photo Galleries/Fergie's farewell
Pictures from Old Trafford as Sir Alex Ferguson takes charge of his last game at the Theatre of Dreams.
However, speaking to Sky Sports<, Ferguson insisted neither theory was true.
"I decided at Christmas," he said.
"Cathy's (his wife's) sister died. She had lost her best friend and she has been isolated.
"For 47 years she has been the leader of the family. She has made a lot of sacrifices for me."
It was a touching reference to his wife, who has been responsible for bringing up their three children as Ferguson powered along as the most successful British manager of all time.
And he admitted the news nearly slipped out on a couple of occasions before the public announcement, which came a day after the intense rumours about his future first surfaced.
Photo Galleries/United champions
Pictures from the celebrations as Manchester United are crowned Premier League champions.
"It was difficult to keep it a secret," he said.
"Sometimes we nearly blurted it out to the family and we told our sons in March but my brother didn't know until Tuesday.
"I wanted to tell the players first and also my staff. Unfortunately there were rumours going around on Tuesday so we started to speed it up a bit."