If Arsène Wenger, Ivan Gazidis and Arsenal's other powerbrokers thought angry reactions to this defeat were restricted to the club's supporters, and particularly those who chanted "spend some money" after Aston Villa had scored their third goal here, they would be wrong. For dissent is also coming from above, with the club's honorary vice-director, Lady Bracewell-Smith, also demanding change at the Emirates.

"Bring Davie Dein [back] and give [Alisher] Usmanov representation on the board if we are to have success going forward," tweeted Bracewell-Smith on Sunday night, having also expressed her "regret" at selling her 15.9% stake in the club to Stan Kroenke in April 2011 and allowing the American to become Arsenal's majority shareholder ("And how deeply I regret selling to Kroenke").

Criticism from the 57-year-old is not new – in June 2011 she called for the board to go, describing it as "passé" – but an intervention from a figure of clout, and particularly one containing the fans-pleasing call for Dein to return and the Kroenke-baiting desire to see Usmanov given influence at the club, is not what Wenger, in particular, would have wanted after a defeat which turned the Emirates into an arena crackling with anger and despair.

The Arsenal manager defended his lack of activity in the transfer market this summer, insisting work was being undertaken "24 hours a day" to add to the arrival of the French striker Yaya Sanogo. But there was also an admission that after this early setback his team are facing another examination of their talent and temperament.

"I do not deny this is a massive disappointment," conceded Wenger. "I believe our season will depend on how we respond to this defeat."

Much then hinges on Wednesday's Champions League play-off first-leg tie with Fenerbahce but Arsenal hardly travel to Istanbul in the best of shapes. Not only is confidence low but the squad's injury list has reached a critical level, with fears that Alex Oxlade-Chamberlain faces a lengthy spell on the sidelines after undergoing tests on his left knee that have reportedly indicated ligament damage. Bacary Sagna has joined Mikel Arteta, Thomas Vermaelen and Nacho Monreal in also being ruled out of the contest. There are also concerns over the fitness of Kieran Gibbs, Aaron Ramsey and Tomas Rosicky.

"We have trouble to recover some players for Wednesday but we have given the [squad] list to Uefa so we can only play with the players we have," said Wenger. And that, fuming Arsenal fans would suggest, is the point. The club have had three months to add to their squad and appeared set to do so when Gazidis, the chief-executive, boasted in early June about an "escalation in our financial firepower". Yet the key targets Gonzalo Higuaín and Luiz Gustavo have moved elsewhere while links to Wayne Rooney and Luis Suárez are burning away. There has been a quality shortage for some time and now there is a quantity shortage to deal with days before a tie which threatens Arsenal's participation in the Champions League for a 16th straight season, a level of consistency Wenger has increasingly pointed to as the trophies have dried up.

With such little business done over the summer, Wenger was asked if it is the case that Arsenal were no longer an attractive proposition for Europe's top talents. "I believe we are," he said. "For instance, I think Arsenal are more attractive than Monaco but it doesn't stop players going to Monaco. In that case it is about the money."

Wenger has two more weeks to spend Arsenal's money on a team that created chances against Villa but were ultimately out-thought and out-fought by Paul Lambert's side. The visitors looked doomed after going behind to Oliver Giroud's early goal but, inspired by Gabriel Agbonlahor, they took the lead through two Christian Benteke penalties, the second of which came about in controversial circumstances when the referee, Anthony Taylor, deemed Laurent Koscielny had caught Agbonlahor as he drove into the area. Replays suggested the defender got the ball first, making the booking he received harsh and even more significant when a further a foul on Andreas Weimann led to his dismissal.

Villa deserved their victory, however, which was sealed by Antonio Luna's counter-attack finish., displaying a level of ruggedness that was lacking in the previous season as they battled against relegation. "We've learnt from last year," said the Villa captain Ron Vlaar. "Mentally we are stronger." It is now up to Arsenal to prove their mental strength.

Man of the match Gabriel Agbonlahor (Aston Villa)