Barcelona beat Leganés 2-1 at Butarque on Saturday afternoon and are top of the table. Undefeated, they also lead their Champions League group, ahead of Internazionale and Borussia Dortmund. Win on Wednesday night and they will be mathematically qualified from the competition’s hardest group with a game to spare. They have lost just one of their last 11 matches, winning nine, and have scored more league goals than anybody in Spain: seven more than second-placed Real Madrid and more than twice as many as Athletic Bilbao in fifth, Atlético Madrid in fourth and Sevilla in third. When they played Sevilla, they put four past them. They stuck four more past Celta and five past Betis, Valencia and Valladolid.

They have the striker who scored 115 over the last four La Liga seasons, more than anyone except that guy, and they have that guy too – the best player in their history and maybe anybody else’s history either. They won last season’s league, making it four of five, and were a goal off a probable treble. Then they signed Europe’s two most wanted players, even if neither was their players’ most wanted: the €75m midfielder made for them, voted Europe’s best, and the summer’s most expensive footballer at €126m. Their new front three had scored 401 league goals in five years; their goalkeeper might be Spain’s best; they signed the full-back Bayern, Madrid, City chased; have the kid exciting everyone; and this weekend’s starting XI cost €489m.

And they’re not very good.

A few days ago in his latest interview squeezed between sets at the Davis Cup, Gerard Piqué insisted: “If we’re top, we can’t be playing that badly.” But, yes, they can. A couple of days later, Ernesto Valverde asked why so many questions start with are you worried that…?, when the answer is obvious: because they’re worried. And it’s not going away; it’s getting worse. That day, Ernesto Valverde said he always leaves the press room suddenly “worried about a whole load of things”; on Saturday, he laughed when a journalist sought a way of asking if he was worried without asking if he was worried, but they still were, even if he wasn’t – or wasn’t showing it. More, in fact, than ever before.

The headline on the front of Sport summed it up: “A worrying victory.”

Another one. Saturday’s result against Leganés is an improvement on last year – Barcelona were beaten then – but nothing else is. A goal down after 12 minutes, Youssef En-Nesyri bending a beautiful shot into the top corner, Barcelona turned it around with strikes from Luis Suárez and substitute Arturo Vidal. Afterwards Valverde admitted it “wasn’t brilliant”, which was one way of putting it. Check the papers and there were others: “abhorrent,” “frightening,” “filthy”. Most importantly, it felt like a portrait of what Barcelona have become. As Francisco Cabezas neatly put it in El Mundo: “Arturo Vidal rescued Ernesto Valverde’s Barcelona at the team that’s bottom. It’s impossible to find a better metaphor for our times.”

If that might not be entirely fair on Vidal, the man everyone except the four-year-old with the mohican and the biro beard loves to hate when they shouldn’t – Vidal is much more Barça than it seems, the one midfielder to press, move, run, score goals – there was something in it. “Arturo Vital,” ran the front page of El Mundo Deportivo, and when he is vital, coming on to rescue you, there is a problem. “The feelings we’re left with are bad ones,” the Chilean admitted.

A win does not hide that, or shouldn’t. Barcelona started by gifting Martin Braithwaite an opportunity inside two minutes and completed a comeback thanks to a header from a free-kick and a scuffed finish off a deflected corner, from which the only reason Vidal wasn’t miles offside was because the ball bounced back to him off an opponent’s leg. They did so at the team that have won once all season. Yes, Piqué hit the post, and Pichu Cuéllar made a superb save from Luis Suárez. Yes, Barcelona had most of the ball. And, no, conditions weren’t good. But this was no siege, no avalanche of opportunities, and no one-off. Instead, Butarque laid Barcelona bare.

Barcelona started with four forwards and no idea, an empty space where one of the interiores should be, playing a sort of 4-1-1-1-3, maybe a 4-2-4, if you could call it anything at all. Slow, lacking ideas, barely able to open up lines of passes, they gave the ball away 135 times. Most the time, it wouldn’t be an exaggeration to say they didn’t know what to do.

“I try to read my teammates’ movements, but it’s difficult,” Antoine Griezmann said recently. “It’s all new for me. I still don’t understand the runs of Suárez, Messi or Dembélé. I still lack the confidence to pass or shoot, but it will come.” Forced into a left-sided role, nor do they understand his movements and if it might come, it hasn’t yet. The case of Ousmane Dembélé, now in his third season, is even more startling. Neither man did anything of note on Saturday. Again. In midfield, Frenkie de Jong is the only regular starter imposing any rhythm on the game, and he’s finding his options limited. At the back, they’re overrun when pressed, lacking focus and football. But their dysfunction was most noticeable was at full-back, where Junior Firpo didn’t know where to go or what to do, unable or unwilling to overlap.

This was not Saturday, this was systemic. Deeper even than that: it goes to the top, speaks to a culture, an environment where players are accommodated, Barcelona “losing the ball, their play, their soul” in the words of El País’s Ramón Besa; a place where there is little leadership or clear direction. It was striking to hear Piqué, the organiser of the Davis Cup who admitted that some nights he sleeps only four or five hours and who spent the last few days travelling back and forth to Madrid, say that his manager asked him what the plan was this week. And it is hard to avoid the suspicion that Barcelona will pay for it. Already have, in fact: you can’t demand a team wins all the time, but Rome and Liverpool were not just isolated accidents and 2015, Barcelona’s last Champions League success, feels a long way away now.

Win on Wednesday against Dortmund and they’re through; lose, though, and they will have to go to Milan needing a victory. Next Sunday they face Atlético at the Metropolitano. Barcelona have only won four of their last 15 Champions League games away, and they have won fewer than half their league games away this season. Defeated three times this season – as many times as in the whole of last year, three times as many as in the year before – this is their worst start on the road for eighteen years. In the meantime, Real Madrid are starting to come good. Winning when you’re not playing well is a sign of a title-winning team, they say, but just as often it’s the sign of a team reality will soon catch up with. Only one of their last seven goals has been scored from open play.

If you don’t know why you won, you won’t know why you lose either. If there is no clear system, the system becomes Messi. Instead of taking refuge in the structure, they take refuge in him – which says something about personality as well as play, about the lack of a model offering alternatives. And while give the ball to the best player there may have ever been might be a logical enough plan sometimes, it can’t be your only plan. It becomes an abdication, removing responsibility, weakening them and him. Just because he often does it “alone” doesn’t mean he should. Or even that he wants to. There is a reason Messi wanted Neymar – a player who was not only good but knew it.

It is often said Barcelona were not that good over the last two years with Valverde but it is not entirely true. The flaws were there, deepened at Anfield but not created there. They have been better than anyone else in Spain, and if it was not pure, if they were losing their religion, it was sometimes good. If this was coming, it wasn’t here yet – not always, not quite like this. This is worse; there’s a better squad but their problems weren’t addressed, including the role of their manager. And now they’re all exposed. On a cold, windy Saturday in Madrid, Barcelona beat Leganés to stay top of the table. “We’ll take it as a good thing,” Valverde said. “We had to win any way we could.”

Outside, the team bus was waiting. Blue and orange, unmarked, as it headed out of Butarque and down the road, no one could tell it was Barcelona on board.