Lack of quality is real concern for sad Arsenal
To judge the way the Arsenal players left the Westfalenstadion on Tuesday night, solemn-faced and mostly unwilling to speak, you could be forgiven for thinking this was one of those evenings in early March when traditionally their Champions League adventure comes to an end.
Rather, this was the club's first defeat in any competition since April 6, and the first game of six in a group from which, in spite of the quality of Jurgen Klopp's Borussia Dortmund side, Arsenal should expect to qualify from, at the very least.
They will have a chance to try to put this 2-0 defeat right when Dortmund come to London on November 26, by which time Arsene Wenger will hope his new signings are better settled.
Mikel Arteta's assessment that Arsenal would not win the Champions League playing this way was inarguable – but they will surely not play this way that often.
Alex Oxlade-Chamberlain captured the mood best when he said it was less the result and more the performance.
"We have had heavier beatings," he said, "but it was not what we wanted results-wise, performance-wise."
The Champions League's first round of group matches is not when any of the big issues are decided but it is an interesting glimpse into a team's potential.
Arsenal have not lost their first group game since 2003, and the significance of Tuesday goes a little deeper than that.
Dortmund delivered the kind of attacking performance that you expect of Arsenal – and all of it done on a relatively modest budget. The German club lost free agent Robert Lewandowski to Bayern Munich this summer, following Mario Gotze's move there the previous season.
They spent around £40m this summer, including £15.5m on Ciro Immobile. Like Arsenal, they too had players missing, including Marco Reus, Ilkay Gundogan and Jakub Blaszczykowski.
It is that kind of against-the-odds attacking performance which has represented the best of Wenger's Arsenal over the years.
It was hard to ignore the fact that Klopp and Dortmund were playing Arsenal at their own game – and winning handsomely.
It was not hard to pick out Arsenal's problems against Dortmund. Arteta was too exposed, a cumbersome defence was not helped by Hector Bellerin's inexperience and Danny Welbeck's finishing let him down.
The nagging concern is that, having made a net spend of £50m this summer, Arsenal are not significantly better equipped in Europe than last season.
In the positions they have strengthened, with Welbeck and Alexis Sanchez, Arsenal will be better over time. In the long term, the injured Mathieu Debuchy and Calum Chambers will improve.
But Arteta and Mathieu Flamini are a year older and no more suited to solving the inadequacies that Arsenal face in midfield than they were last season.
Oxlade-Chamberlain said: "We cannot look too much into results. You cannot get tied up putting pressure on yourself.
"We want to win but you have to focus on how you play. We know we need to start winning games."
His message being that with good performances the results will come, in what has been a slow rather than a disastrous start to the season.
The problem being that Tuesday was nowhere near the performance level needed, and it was Dortmund, not Arsenal, who showed Europe what a good team they have.