Misfiring Gunners need to reload to maintain title shot
Arsene Wenger resorted to his default description of "naive" defending in explaining another chastening Champions League defeat on Tuesday night but it was actually captain Per Mertesacker who diagnosed the more urgent problem.
"We had to score at one point - that was the key to why we lost," said Mertesacker.
He was right. It was always going to be virtually impossible to prevent at least one game-changing moment of sweeping Barcelona brilliance and a surprise of the evening was that it took until the 71st minute for Arsenal to be unlocked.
The wider narrative of the game was also the issue that most threatens Arsenal's challenge for a first Premier League title since 2004: their uncharacteristic lack of attacking certainty.
Chances were inevitably few and far between on Tuesday -
Alex Oxlade-Chamberlain, Olivier Giroud and Alexis Sanchez conspired to miss what little they did create, but Arsenal have now failed to score in five of their past eight games. What goals they have summoned in the past six weeks have been against Burnley, Bournemouth and a Leicester City team who were down to 10 men.
For all their reputation for creative fluency, Arsenal are the lowest scorers of the four clubs who are contending to win the Premier League.
Giroud has now gone eight games without scoring, while Theo Walcott, the other main striker, has one goal in his last 13 appearances.
The goal records of the other main attacking options are hardly reassuring. Aaron Ramsey has gone six games without scoring; Alex Oxlade-Chamberlain's 14 Arsenal goals are spread over five seasons and 148 appearances; Danny Welbeck has nine in 37 appearances and Joel Campbell three in 33.
Crucially, the two best outfield players are experiencing a dip in their usual standards. After setting up 17 goals in the previous 24 matches, Mesut Ozil has one assist in his last seven games, while Sanchez, who is still accumulating match fitness following his hamstring injury, has not scored in the league since October or in any of the five matches since he returned.
It is a collective issue that Wenger regards as cyclical but is clearly reluctant to publicly dissect for fear of deepening any crisis in confidence.
"We were impatient in the build-up," he said. "We had an unbelievable chance (for Oxlade-Chamberlain) and the way we finished our chances is a problem. I feel that in the final third, at the moment, we miss something."
Many supporters will point to the decision not to sign another striker since Welbeck joined 16 months ago and that frustration will be compounded in the coming week when interim accounts will again show a vast cash reserve.
Arsenal will stress that an estimated £200m balance must also fund day-to-day costs and does not represent the actual available budget but there is little doubt that at least one other major signing was financially feasible.
It was Wenger's favourable judgment of his current squad against what was available in the transfer market that shaped the club's strategy.
There is considerable personal pressure, then, for him to now inspire a renewal of their attacking cohesion. Santi Cazorla is targeting the second leg against Barcelona in three weeks for his return and he will make a big difference to the team's balance but Wenger must also now yearn for Ozil, Sanchez, Walcott, Giroud and Ramsey to recover their most incisive form.
None other than Lionel Messi remains certain that Arsenal do have the artillery to hurt Barcelona in the return but, like Mertesacker, always sensed that his team could not be indefinitely contained.
"You have to score at one stage against Barcelona to keep the pressure on them," said Mertesacker. "We were doubted a lot but you can't say that we have defended badly. You will never keep them quiet for 90 minutes. It was a bit naive but when you keep going for such a long time and keep up with a good team you have to score. We couldn't get over it."
Petr Cech, who had previously lost only once in eight matches with Chelsea against Barcelona, agreed.
"The only thing we didn't do well was take our chances," he said. "In games like this you need to be more clinical. They had three or four chances and we had the same."