The Red Devils are in alarming form despite spending large amounts of money on a number of players this summer.
Jose Mourinho's side have lost their last three games in a row in all competitions, after beginning the season brightly with three straight wins.
Despite spending huge sums to bring in the likes of Paul Pogba, Eric Bailly and Henrikh Mkhitaryan, the Red Devils have yet to fully connect as a fully functioning unit.
Yorke, who was part of United's treble-winning side of 1999, believes this is the reason for their dip in form, and fears that Mourinho's men seriously lack the creative edge to defeat their opposition.
"When you play with the calibre of players I played with, you talk about creativity within the midfield, people who can pass the ball forward, and I think that is something they are lacking," Yorke told talkSPORT.
"They lack someone with that vision, who can see that pass, that penetration, within the team. Roy Keane, for instance, used to bulldoze his way through teams but also could see the pass as well and pass forward and really kick-start the attack. That is something United have been lacking.
"You look at the quality they have in midfield, the most expensive player should be bulldozing his way through people and he has not really done that yet.
"Even in a holding midfielder, we had somebody that could pass a football. You need that sort of creativity and we haven't been able to do that.
"Teams are really not fearing us as they used to and that is something we need to get back. We need to run over teams like we used to do."
United's creative edge has definitely declined in recent games,and they look a shadow of the sides that used to strike fear in their opposition with completely dominant creative play.
If Mourinho is able to reinstall that fear factor, it could go a long way in resolving the Red Devils' worrying run of form.