How anyone could think the incoming Dutchman could inherit the same mob of players and expect to be rosy again is simply beyond me. There were a few small buds of hope (more on that later) but this was, largely, a case of same shit different day.
Irritating cliche though it is, it's hard to imagine ten Hag watching his side completely outplayed by the ninth best team in England - a side which sold it's two best players - with anything other than a dawning realisation of just how much work there is to do after a pre-season which did show promise.
93 days on from the nadir of Ralf Rangnick's miserable interim spell in charge, the infamous 4-0 thumping at the hands of Brighton, not much has changed.
Despite losing two of the stars of that famous win in Yves Bissouma and Marc Cucurella, Brighton were just as vibrant, just as savvy, just as well drilled and just as good at basically everything.
Graham Potter has done a simply impeccable job on the south coast, turning the Seagulls from perennial strugglers into an upwardly mobile team every other club now aspires to be.
United had looked strong and impressive in pre-season but wilted in the Manchester sunshine once the pressure was on in front of a full house on the opening day of the Premier League season. When the going got tough, the match lapsed into a familiar pattern. Heads dropped, any semblance of cohesion trickled away, touches became heavy and passes loose. Only when Cristiano Ronaldo - the same Ronaldo who, indeed, wants to leave came on did United show any signs of an upturn.
Christian Eriksen shone on his full debut as he linked the play, looked good on the ball and caught the eye with his eclectic range of passing. He came close to scoring and United's best spell of the game came when the talented Dane dropped deep alongside Fred and began to dictate the game. Still early days but Eriksen could be a very good signing for the club.
£57m man Lisandro Martinez had a largely impressive debut alongside Harry Maguire and there were signs the pair could become a strong and dependable centre-back partnership, given time and patience.
Donny van de Beek did more in his flashing 12-minute cameo than Scott McTominay managed in the 78 before him, but that was where the positives ended. But like an amateur golfer improving his swing or a plastic surgery obsessive, any improvement, however minor, only serve to emphasise other problems.
And so we come to the proverbial elephant in the room. Size wise, the 6ft 4 frame of Scott McTominay towers over the diminutive, 5ft 10 Moises Caicedo but it was Caicedo who simply bullied his opposite number into submission. The young Ecuadorian bossed proceedings and was the best player on the pitch, in the first half especially, as he cut a swathe through United's anodyne, non existent midfield.
The ease with with Brighton sliced us open through the middle was down to the ineptitude of McFred as much as it was due to Caicedo's expertise. For three years, we have witnessed these plodders melt away and turn our midfield to a pile of rubble. They would not start for any other Premier League team or, indeed, most of those in the Championship. Games are won (and lost) in midfield. Every top side dominates the midfield, control the game and they win. ten Hag knows they are incompatible and about as much use as a chocolate fireguard, but he has to play them as there is no one else.
For now at least, ten Hag has to be absolved of any culpability. As is the case for any new signing arriving in a new league, it takes time for managers to find their feet. Time and patience is the only way forward for United. ten Hag perhaps failed to cope with the necessary speed of decisions and how to react, but he has to be allowed to learn on the job.
United missed a trick by not making a move for Bissouma but Caicedo is exactly the kind of player we need in the middle of the park. An orchestrator, a string-puller, not shy of wanting the ball and relentless in the press.
He covered every blade of Old Trafford's sun-kissed turf, picking holes in United's set up, mopping up the danger and paving the way for his forward players to inflict the damage.
Yet the biggest irony of all? He could have been doing that for us. He was available for next to nothing, £4.5m - United held extensive discussions with him over a deal but, as per, failed to get anything over the line. We don't have the nous or the guile to cherrypick such gems, instead faffing and faltering for an eternity trying to sign a player in Frenkie de Jong who does not even want to come.
Now he is worth around ten times in yet another glowing endorsement of Brighton's exquisite scouting network and recruitment strategy. In short, they are everything United aren't. The biggest compliment you can give them is they have lost Bissouma and Cucurella but yet you would not even have noticed.
United need more, a lot more, most notably in midfield when McTominay and Fred are simply not good enough. That line of thinking has been the case for the best part of two years now, yet United have failed to rectify the problem and continue to persist with the invisible pairing.
Assuming a return to the top four is the aim, ten Hag requires an astronomical upturn in performance from his new United side. He himself will have to climb Everest in slippers - the steepest learning curve in world football.