The word used by many pundits was "transitional"—yet since Moyes took the reins in July, it has been more a case of "upheaval."
Having suffered five Premier League defeats already this season, the defending English champions find themselves eight points off table-toppers Arsenal, who have played one game fewer.
Eighth in the league, United have now been faced with the stark reality of top-four consolidation rather than title retention.
But why has it gone so wrong for United? Does the problem rest solely with Moyes, who has yet to prove himself at this level, or should some of the players shoulder the blame?
With a January transfer window fast approaching, next month is a chance for Moyes to get rid of some of the deadwood at the club and stamp his own imprint at Old Trafford in this post-Ferguson era.
And here, B/R takes a look at five problem areas David Moyes must target in January.
Patrice Evra has been a loyal servant to Manchester United since joining from Monaco in 2006.
In over 250 appearances for the club, the Frenchman has won five Premier League titles, three League Cups and the Champions League—but at 32, he now finds himself in the winter of his career.
That David Moyes went in for two left-backs over the summer in Fabio Coentrao and Leighton Baines is perhaps indicative of the Scotsman's lack of faith in the veteran full-back. Evra has lost that crucial yard of pace through age and has also been tipped with a return to Monaco next summer, per Sami Mokbel of the Daily Mail.
With the jury still out on understudy Alexander Buttner—the Dutchman was badly at fault in the build up to Carlton Cole's goal for West Ham on Saturday—a January replacement would be wise.
Widely considered one of the best in his position and set to usurp Ashley Cole in the England team at next summer's World Cup, the 29-year-old is once more being tipped with a move to Old Trafford in January.
As well as left-back being a problem area at Old Trafford, so too is centre-back.
Rio Ferdinand and Nemanja Vidic, the rock-solid defensive foundation upon which much of United's past successes have been built, are no longer reliable, with age and a patchy injury record keeping the duo out of the side.
At 35, Ferdinand doesn't have much left in the tank, while Vidic has missed his side's last two games with a knock and only managed 25 league appearances between 2011-12 and 2012-13 with a knee injury.
And though Jonny Evans and Chris Smalling have sometimes admirably stepped into the breech to cover for the two, neither can be described as world-class centre-halves.
The same argument applies to Ferdinand and Vidic as it does Evra—United need to buy in a quality replacement in the New Year to shore up a defence that has already conceded 20 times this season, which, alongside neighbours City, represents the joint-worst defensive record of any side currently in the top five.
Ashley Young has scored two screamers for Manchester United in the space of a week—against Stoke in the League Cup and West Ham in the Premier League—but even those strikes will not be enough to save his Old Trafford career.
Not if David Moyes has any sense.
The England international has been frequently dire this season, called out for, and then mocked, for his penchant for diving. He was hooked off seven minutes after half-time in the 4-1 defeat to Man City back in September, a fixture that represented arguably his worst-ever performance for the club.
In the wide areas, United have been as unimaginative and ineffectual as they ever have been this season, and Young isn't the only culprit. Nani, who was handed a new, five-year contract at the club recently, would consider himself incredibly fortunate were he to see it out, while Antonio Valencia hasn't quite been the same player since suffering his horrific leg-break against Rangers in 2010.
Meanwhile, according to Matt Law of the Telegraph, flier Wilfried Zaha looks fated for a January loan move, having failed to make much of an impression at the Theatre of Dreams since arriving from Crystal Palace. Combined with the probable unloading of one or two under-performing stars in the New Year, that will put Moyes bang in the frame for a new winger next month.
Considered to possess the Premier League's most lethal strike force in Wayne Rooney and Robin van Persie, perhaps one or two of you will be wondering why United can be said to have a problem up front.
The answer to that can be found in injuries as well as continued speculation linking each striker with a move away from Old Trafford.
RVP will be out until the New Year with a thigh injury—the latest in a series of niggles that have sidelined the Dutchman for five of his side's last six league games—while Rooney too has struggled for fitness.
Then there are the rumours linking each forward with an exit from the club next year. Football pundit Mark Lawrenson recently claimed van Persie has handed in a transfer request while Chelsea retain an interest in his teammate Rooney, per Mirror.
It would be a savage blow were United to lose either star in 2014, and Moyes would clearly have to look into signing a new striker should such eventuality play out.
The Scotsman may have to enter the market for a new forward in January regardless of van Persie and Rooney's respective situations, as Javier Hernandez has threatened to leave over lack of playing time, per the Daily Mail.
Given the injuries to Rooney and van Persie recently, United would struggle to cope with just the one understudy in Danny Welbeck.
Of all Manchester United's problem areas, centre-midfield is arguably the one most in need of attention, with as many as three stars failing to pull their weight in the middle of the park.
Question marks were immediately raised over the size of his price tag, which he has thus far failed to justify, while a series of back and wrist injuries have combined to keep him out of the side, wrecking the first half of his debut season.
Then there's Tom Cleverley, who has, I think it's fair to say, completely failed to live up to his potential having once been billed the "next Paul Scholes." Having found himself in and out of the side all season, his one league goal this term is hardly comparable with the mercurial talents of the ginger magician.
And we haven't even yet touched upon Anderson, the Brazilian flop who must surely be on his way out next month after six-and-a-half underwhelming seasons at Old Trafford.
David Moyes attempted to address his midfield over the summer, making a series of bids for Cesc Fabregas. Moyes was also linked with the likes of Thiago Alcantara, per Metro, and Ander Herrera, per Jamie Jackson of The Guardian.
In the end, he only brought in Fellaini, and the Scot cannot afford to suffer a similar lack of success in the January transfer window.