"I've seen Sir Alex Ferguson on Monday at a charity game," the former Trinidad and Tobago international told Sky Sports News. "He was in good spirits but the rumours were really strong around the place that he was going to retire and there was a big announcement supposed to be happening tomorrow and not today.
"I think probably the fact of the club floating on the stock market meant this decision needed to come out very quickly. But the people within the football club knew this was likely to happen this season."
He added: "And I think with his hip replacement (booked in for late July), with David Gill going as well, that sort of pushed him to say 'this might be the best time for me to retire'."
Yorke expects there to be a strange atmosphere in the immediate wake of Ferguson's departure from the helm.
"He's been such a focal point at the football club," he said. "He's taken Manchester United to the level they are at right now.
"It's a shock to the system because he's been there every day. He's the one person when you go into the football club he's always there. For him not to be there from the start of next season, it's not going to be right around the football club and it will take some getting used to."
Ferguson, of course, will be bowing out on a high having regained the Premier League title after being pipped to the crown by rivals Manchester City in dramatic circumstances on the final day of last term.
"He has very, very high standards and it's all about winning trophies and breaking records with Sir Alex Ferguson," Yorke continued. "But there's more to the man. How they lost the Premier League last season - that would have hurt him immensely. Certainly losing it to Manchester City, that would have hurt worse than anything else.
"He wanted to regain it and he's managed to do that in a great way and with a great style of play."
Source: PA
Source: PA