The surprising loss to Fleetwood, a team 84 places below Arsenal in the football pyramid, was made even worse by the fact that the Gunners’ under-21 team had beaten AFC Wimbledon, a side in a division higher than the hosts, on the same night in the EFL trophy.
The first incident of the match came with under two minutes on the clock when the game was stopped for more than eight minutes when a drown was flown above the pitch.
Perhaps Arsenal should have taken that as a warning.
Arteta named an experimental side and gave a debut to 18-year-old Ceadach O’Neill, started 17-year-old Marli Salmon at centre back, 16-year-old Dowman on the wing while goalkeepr Illan Meslier was making his first start for the club too.
But the Gunners boss surrounded that inexperience with seasoned internationals such as Jurrien Timber, Piero Hincapie, World Cup winner Martin Zubimendi, Champions League winner Kai Havertz and Viktor Gyokeres.
All of those players played a huge part in the Gunners winning the Premier League title last season.
However, even after introducing captain Martin Odegaard and £75m signing Bruno Guimaraes from the bench, Arsenal produced a poor performance.
“First of all, congratulations to Fleetwood for going through the next round. The manner that they have done it, and for us a very sad day.” Arteta said of the result.
“There is nothing to criticise the players for their attitude, their application. The determination – you could see that was there from the start.
“Even with 10 men, we conceded a really poor goal to start with that gave them some momentum.”
The loss in this competition is not the Gunners’ first, but it does mean they have not won the League Cup for 33 years.
In 2012, Arsenal lost to League Two side Bradford City on penalties and they were also beaten by Championship side Sheffield Wednesday in 2015 at the same stage too.
With Dowman now suspended, Saka out for around six weeks, Tzolis working to return and Arteta revealing after the match that Madueke was unavailable with an injury, their options in the wide areas for the match with Liverpool on Sunday are looking slim.