Arsenal chief executive Ivan Gazidis has issued an apology to the supporters that travelled to Valley Parade on Tuesday night.
The Gunners crashed out of the League Cup on penalties to League Two side Bradford City after trailing for much of the 90 minutes.
Gazidis admitted that the performance had been well below the required standard but was adamant that the club will work hard to put things right.
He told the Arsenal Supporters Trust: "It was not good enough and it made us all upset and angry.
"I would like to apologise to all of you, especially the fans who travelled up there.
"It was unbelievable support, as ever, and you deserved better. That is something we will work hard to put right."
Arsene Wenger's side are back in Premier League action on Monday night when they face Reading at the Madejski Stadium.
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