While many people were surprised that the club captain didn't even feature on the bench against Liverpool, there was always a sinister undertone when Sir Alex referred to tightness in the knee.
One thing is for certain. United cannot afford another season without their talismanic captain.
It's not just the absence of probably the key defender, it is the knock-on effect throughout the squad. Furthermore, I was always concerned whether Vidic would come back as good and fit as he was before last season's injury. That was why Javi Martinez seemed such an attractive signing, being able to fill in at defensive midfield.
Failing that, other options were mooted, including Neven Subotic.
For all the talk that the title last season was lost against Everton, or at Wigan, the harsh truth is that one of the worst injury crises ever at Old Trafford was the real cause. United lost almost 1,700 player days last season compared to City with less than 190.
That's all history now.
Which is why Sir Alex needs a radical rethink in defence, starting against Newcastle today.
Even while there were apparently three centre backs fit it made no sense to play any of them against the Toon, so the suggestion yesterday was that Keane, Wootton and Fornasier should all start at the back.
There is a desperate need for him to look at the next generation in a competitive situation. It's all very well sending Keane, Wootton and Blackett on tour to get experience, but when are they going to get a game?
It's like Ferguson constantly dusting off Scholes and Giggs when Cleverley, Anderson and Powell are kicking their heels. He trusted the class of 1992, so why not now?
Maybe Ferdinand and Evans will be fit for Tottenham, but Newcastle, Stoke and Chelsea are up before Phil Jones will be back playing; and Chris Smalling may not be match fit much before then, even if he meets his injury timetable of 7 October.
In a crisis like this, Sir Alex daren't rush players back. Look what's happened to Vidic through having to play him every week.
The experiment with Carrick at CB simply must not be repeated. Carrick was excellent against Everton and Fulham, but it is not fair on the player, no matter how willing he is; nor would it be with Darren Fletcher.
It's time to place faith in the next generation. Surely at least one of them will be better than a midfielder pressed out of position. Somebody needs to be sharp before Stoke City arrive, that's for sure.
And have we already forgotten that a makeshift defence including Carrick was thrashed by Newcastle away last season. We don't want deja vu on 7 October.
It has been said for too long that Scott Wootton is highly rated by the coaching staff. He had an excellent season at Peterborough and Forest. It's time to find out; he'll either make it or he won't.
Michael Keane has five caps for England U19s and Tyler Blackett (who can play at left back or centre back) already has one.
In fact United have never been more blessed in terms of young central defenders, which may have in part conditioned Zeki Fryers' decision to leave.
Listed in the Premier League first-team squad, in addition to Wootton, Keane and Blackett are:
Tom Thorpe and Freddy Veseli
In the Champions' League squad only Keane is listed, so is it time for him to get his chance?
There are still others with the potential to make the first team. The Under 21s squad for United (formerly the reserves) lists, in addition to the above:
Sean McGinty, Luke McCullough, Michele Fornasier and Reece Brown (younger brother of Wes, who is on loan at Coventry City).
So, Sir Alex is apparently spoilt for choice, but he seems to have backed himself into a corner.
The team's performances have not been that great so far and as a result he keeps going for safety first, either playing his two big signings or veteran players, even if they will be 38 and 39 by the time Vidic returns.
Brendan Rodgers and Andre Villas-Boas have shown him the way, blooding young players due to shortages in their squads. Raheem Sterling (17), Jonjo Shelvey (20), Steven Caulker (20) and Andros Townsend (20) have already shown that if you're good enough, you're old enough.
Whether by accident or design, Ferguson's gamble with the Class of 92 proved to be pivotal in the astonishing era that has followed.
Giggs, Scholes, Phil Neville and Beckham are still playing at the top level 20 years later. Who is to say that one, two or more of these young defenders cannot emulate that feat.
The same goes for Nick Powell and the other young players who should get their chance against Newcastle.
Jonny Evans, Rafael, Fabio, Cleverley and Amos have already emerged as first-team footballers from the Academy. If just one of the nine centre backs listed above turned out as good as these, it could save United £15-20 million in transfer fees and take the heat out of yet another injury crisis.