"I'd also like to remind you that when we had bad times here, the club stood by me, all my staff stood by me, the players stood by me," he said in May, urging them to get behind David Moyes, the man he had helped chose to succeed him.
"Your job now is to stand by our new manager. That is important."
It was a moment of gloomy prophesy to dampen the mood of yet another league title, but the boos that greeted the final whistle of United's 2-1 FA Cup defeat by Swansea on Sunday suggest Ferguson's words have fallen on deaf ears.
The patience of those who flock to Old Trafford and have witnessed unparalleled levels of success in recent years is being tested to the limits after the succession took another stuttered step backwards.
Sunday's reverse was United's fourth home defeat in their last six.
Out of the FA Cup in the third round for only the second time in 29 seasons and languishing seventh in the Premier League, United fans are wading through largely unchartered territory.
On a day for statistics, it was appropriately the first time Swansea had ever tasted victory at United's home ground.
For all Ferguson's talk about a darker period at the start of his tenure, the gloom currently encircling Moyes is perhaps more pronounced.
It took Ferguson 44 games to lose five at Old Trafford, and that was with a team who had not won the title since 1967.
Moyes has reached that inglorious mark in just 16 matches and with a side who won the title in May by 11 points on the back of two decades of solid success.
LACK OF CREATIVITY
The United manager put Sunday's defeat down to a lack of creativity.
"I think we played quite well in the first half, we got near the edge of the box quite regularly, but we didn't quite make the opportunity to score more goals," he told BT Sport.
"That was the disappointing thing as we'd come back from a goal behind and I thought for long periods we had control of the game, but we didn't get a goal or create enough chances from it."
The United fans, however, are starting to question whether United's current lack of spark is down to Moyes himself.
The message boards on the club's own website (www.manutd.com) were ringing with criticism for a man who did not win a trophy in his 11 years at Everton.
"He is a good manager but not a WINNING manager," was the opinion of one contributor called Rylands.
"The repercussions of finishing out of the top four are huge. The inevitable loss of revenue, the loss of our better players ... the inability to attract top players will contribute to a further decline. Eventually Moyes will be sacked. It is just a question of when."
Foxbat added: "It is not the green and gold (protest movement) that needs to be cranked up but the Moyes departure before he completely destroys the whole club. If Bobby (Charlton) and Fergie (Ferguson) are opposing then they should also realise no one is bigger than the club."
Moyes's habit of claiming United had played well in defeat is also starting to grate with fans unused to dealing with consecutive home upsets.
There have, however, been a few glimmers of hope for Moyes, who has comfortably negotiated the Champions League group stages and steered United to the League Cup semi-finals.
Tuesday's first-leg clash with Sunderland provides him with an almost instant means of turning a few more fans back towards Ferguson's way of thinking.