The Manchester club had done a treble and so posed with their trio of trophies. Not the treble, admittedly, because the photo taken on Friday showed Alejandro Garnacho with the Premier League’s goal of the month award, Harry Maguire with the player of the month prize and Erik ten Hag with its managerial equivalent. Perhaps the young Argentinian will conjure something else spectacular, but it already feels safe to assume United will not retain the other two awards.

A day after the picture came a crushing defeat. Perhaps that was Manchester United in a nutshell: the brief sense of progress followed by the evidence there has been none. The markers of improvement and excellence instead belong to others. Bournemouth’s first victory at Old Trafford in their 124-year history made them the latest in a long list of clubs who, over the last decade, have ended a long wait for a win at United’s home.

It also rendered them the fifth visiting side to score three times at Old Trafford already this season, joining Brighton, Galatasaray, Newcastle and Manchester City. The two most frequent scorelines at Old Trafford in this campaign are a 1-0 home win and a 3-0 away victory. In its own way, it highlights how United’s triumphs can be unconvincing, their setbacks emphatic. In the Premier League, they have trailed for more than three times as many minutes as they have led at Old Trafford.

On Saturday, Ten Hag admitted United are not good enough to be consistent. They struggle to play well for 90 minutes, let alone consecutive matches and while the Dutchman likes to cite the draw away to Galatasaray as a fine display, United conceded three goals, two of them due to glaring errors by his chosen goalkeeper, Andre Onana.

The statistics support his broader point – United have not gone four games unbeaten this season – but there are plenty of possible ripostes. They did have the right kind of consistency last season: there was one run of nine undefeated matches, another of nine straight wins, a third of nine victories and two draws in 11 games. Another is simply to point out that Ten Hag has spent £400m. Mediocrity should not be this costly.

The United manager likes to think his blueprint is attacking but only five of the stragglers have fewer league goals. His out-and-out attackers have a mere four between them, one a penalty gifted to Marcus Rashford. Piers Morgan, a man with an innate capacity to be wrong, pointed out that Rasmus Hojlund is yet to score in the Premier League; that is true, but he used it to criticise Ten Hag for dispensing with Cristiano Ronaldo. An immobile, ageing ego and a disruptive presence in the dressing room would scarcely be a panacea for their problems but whereas Ten Hag’s toughness yielded results last season, it is not doing now.

This week marked the 10-year anniversary of the most infamous tweet United have published on social media. “David Moyes says #mufc must improve in a number of areas, including passing, creating chances and defending,” was the 2013 version. Ten years on, United passed the ball twice to Bournemouth for their goals, defended poorly and, despite having 20 shots, hardly created clear-cut chances.

Bruno Fernandes contrived to get booked for dissent, a still greater offence as it renders him banned for the trip to Liverpool, and then admitted Bournemouth “wanted it more”. It was all the more damning as Ten Hag likes to tout the spirit in the camp, trying to use the games when they have scored late goals – like Fulham and Brentford – as evidence that he has not lost the dressing room. Yet there are others when they have been too supine. Even when they have had strong finishes, there have been too many sloppy starts: Dominic Solanke scored in the fifth minute on Saturday. United have conceded more than they have scored in the first, second, third and fourth 15-minute segments of league games this season.

While Solanke starred, United’s centre-forward, Anthony Martial, was dismal. With Hojlund benched, it added to the times when Ten Hag has picked the wrong team, when his replacements have been required to correct his initial errors. There have been seven half-time substitutions in central midfield alone so far this season.

And so they face Bayern Munich and then Liverpool, again looking a mess. Five years ago, Jose Mourinho was sacked after a comprehensive defeat at Anfield. Ten Hag lost there 7-0 last year. He returns with United in a state of flux.

He has enjoyed the backing of the current powerbrokers, of the Glazer family, the outgoing chief executive Richard Arnold and the football director John Murtough. The imminent investment from Sir Jim Ratcliffe and Ineos will add another dimension and a layer of uncertainty. Perhaps Ten Hag will not be a victim of regime change, but for now Manchester United must improve in a number of areas. Including playing football.