It is far too early to panic, of course.
With United still clinging to the coattails of their noisy neighbours Manchester City and games against Queens Park Rangers, West Ham and Reading to come before they take on the champions, it can hardly be deemed a crisis.
They have also achieved Champions League qualification in top place with two games to go. So what’s all the fuss about?
If we are honest, the encounter at Carrow Road was an accident waiting to happen.
So often this season, United have dug themselves out of a hole through sheer talent and obstinacy to sneak games by the odd goal, often at the last minute and often after looking dead and buried.
On this occasion, the Reds’ magic failed them, and Norwich’s resilience proved too big an obstacle for United’s battering ram offensive.
United’s lack of dynamism in midfield, which has characterised much of their play this season, was again a feature of this match. Too much negativity in terms of forward momentum was in evidence, and, on this performance, one wonders where this momentum is going to come from.
Occasionally this season, such as the second half against Aston Villa last week, flashes of inspired play have lifted their game out of mediocrity and offered up chances to the prolific Robin Van Persie and Javier Hernandez.
However, on Saturday, perhaps partly suffering from the absence of Wayne Rooney, the strike duo looked impotent, were starved of decent, early ball from the midfield and were stifled by Norwich’s deep laying defence.
With the exception of matches against Wigan (4-0) and Newcastle (3-0), they have struggled to dominate matches. Out of the 12 other competitive matches they have won so far this season, 10 have been by a single goal and two by two goals.
This, in itself, is perhaps not too concerning. Top sides know how to "win ugly," as the much overused expression goes, and scrape results, but you feel that the tide only has to turn slightly for those wins to turn into draws or defeats.
Also, a side so apparently dependent on the goal scoring prowess of Van Persie will surely become vulnerable if he gets injured or experiences a lack of form.
This year, where are the goals coming from in midfield?
So far, in 18 competitive matches, no midfielder has scored more than two goals, and only 11 of the 43 goals scored have come from midfield players.
Considering many of United’s earlier matches were played with only one out and out striker, that is a pretty poor return from this area of the park, particularly bearing in mind that the back four have contributed seven goals themselves.
There is no shortage of talent in the ranks, but United lack a Keane-like destroyer to provide a solid base for the more creative players to flourish and, in the short term, a player who can make things happen on a regular basis.
I say "short term" because the ultimate potential of players like Tom Cleverley and Nick Powell is undisputed, but they need support so their progress can be nurtured slowly.
We return, then, to the almost weekly call for midfield replacements at Old Trafford, and familiar names once again are being touted around in the press and in the stands.
Sandro of Spurs or Kevin Strootman of PSV Eindhoven would fit the holding role nicely and, at 23 and 22 years old respectively, would suit Sir Alex Ferguson’s policy of recruiting youngsters whenever possible.
Christian Eriksen of Ajax is also a mere stripling at 20, but he already possesses that penetrative, dynamic style that puts fear into defenders. He would fit seamlessly into United’s heart, providing the extra thrust that has been missing for long periods of matches.
It would mean possibly disposing of existing players, although with natural wastage that may not be necessary.
Ryan Giggs was uninspiring on Saturday, and you feel that both he and Paul Scholes need to play regularly to be at their best.
Unfortunately, at 39 and 38 respectively, that isn’t going to happen and therein lies the Catch-22 of the Giggs/Scholes situation.
Realistically, both are likely to be used mainly as impact players from the bench and should not be considered as part of United’s main thrust. They have had their days...and what days they were!
Nani and Anderson have flattered to deceive too many times for my liking, and one or both should be shown the door.
I would plump for Nani, who, despite his prodigious talent, is inconsistent, can be wasteful in possession and is often weak when it comes to decision making.
Also, he would fetch a useful fee, which would probably finance at least one of his replacements above.
There is no question in my mind that, despite the apparent healthy position domestically and in Europe, Sir Alex needs to request that the owners put their hands in their pockets (or someone else’s pocket, in United’s case) and act before it’s too late.
Then, maybe, the tinkle from Saturday will become a distant memory.