It is a crying shame when you witness a great individual fall from their well earned position at the summit of the mountain top.
In the New Years Day defeat at home to Tottenham Hotspur, the back four led by the Serbian were humbled, as the North London team counter-attacked against the champions with consummate ease.
United conceded because of a lack of physical urgency from its defenders, but the problems run deeper than just the two goals that were given away in this game.
During the match it was clear to see how Vidic struggled with his mobility, and if you are the player that has to organise and execute, you must lead by example.
Vidic's failing physical game has been matched by that of Patrice Evra. The Frenchman still has his uses when going forward, but appears to be running in slow motion when retreating into his left-back position.
Both Vidic and Evra have been fantastic servants to Man Utd, but their time is up. It happens to the best of footballers.
One huge issue for David Moyes when playing Vidic is the profound effect it has on Jonny Evans' game. As Michael Carrick sank deeper and deeper in the final years of the aging legs of Paul Scholes, Evans now performs a similar routine with Vidic.
Evans is himself a leader, and a great organisational force for the Red Devils. However, in Vidic's presence he reneges this responsibility by default and his own game is fundamentally compromised.
Whilst partnering either Chris Smalling or Phil Jones, Evans comes to life. He takes control and his partners listen to him.
Even with these three young defenders at their disposal, there is still the feeling that United need a physical entity to replace Vidic.
With the January transfer window now open, United are well placed to address this huge hole at the heart of their engine room.
Eliaquim Mangala would be perfect to take over from Vidic, and has spoken of his love for the Premier League, as per The Daily Star.
Mangala is a beast of a defender, something United was clearly missing in their ranks against Spurs.
They were devoid of a player who could deal with Emmanuel Adebayor's power and movement. In the future, if Evans is to cover and organise, United need a Mangala to do the punishing work.
Of course a player of his quality will not come cheap, but if the Glazers want their football club to be in the Champions League next season, then they will have to push the financial boat out sometime in the next 30 days and not wait until the frenzy of a World Cup summer.
If Mangala or any of his contemporaries shine in Brazil during the tournament, United may well be priced out of the best talent with the most potential.
It would be shrewd business to get their targets now, even if they do have to pay a premium in transfer fees to force the issue.
As we say goodbye to the greatness of Vidic, it is now the correct time to look to the future and bring in his successor.
United need to address their positional problems immediately, otherwise Moyes' chances of being successful as the manager of Man Utd are almost zero.
As Vidic himself was a clever piece of January transfer window business, it would seem fitting that his replacement was brought in under similar circumstance.