The former Trinidad and Tobago international spent four years under the Scot's management - winning three Premier League titles, the Champions League, the FA Cup and an Intercontinental Cup - and feels that his departure will be "a shock to the system".
"It's [a feeling] of shock, really, because he's been such a focal point for our club," Yorke told Sky Sports. "He's been the one to take Manchester United to the level that they are right now and, globally, what he's brought to the Premier League.
"It's a shock to the system because he's been there every day. He's the one person who, every time you go into the club, he's always there. With him retiring, that means he's not going to be around, he's not going to be taking those team talks and decisions. His voice won't be echoing in the background like it has always been. He's been such a great person to the club and, the respect that he had around there, for him not to be there next season, it’s not going to be right. It will take some getting used to."
Asked if it was the right time for the legendary boss to call time on his reign, Yorke replied: "Is the timing ever right with Sir Alex Ferguson coming to his retirement? I don't think so.
"I'd seen Sir Alex on Monday. He was in good spirits, in a very good mood, but the rumors were really strong around the place that he was going to retire and there was a big announcement supposed to be happening, but the fact that the club is floated on the stock market meant that this decision needed to come out very quickly.
"The people within the club knew that this was likely to happen this season and I think, with his hip replacement and [chief executive] David Gill going as well, that pushed him a little bit to say: 'This might be the best time for me to retire'.
"The hip replacement, that was going to take some time to recover, and, knowing Sir Alex, if he is not there and not committed 100 percent, then all of those elements are the ones that pushed him over the edge."
The former Red Devils forward insists that the 71-year-old's hunger remains as strong as ever but feels that the circumstances added up for a logical end to his time at the club.
"He has very high standards and it's all about winning trophies and breaking records for Sir Alex but there's more to the man," Yorke remarked. "The way in which they lost the Premier League last season, that would have hurt him immensely, and losing it to Manchester City was worse than anything else.
"He wanted to regain it. He's managed to do that and he's done it in a very great way, a great style of play, so by doing that, with the hip operation and Gill going, I just feel it's probably the right time."