Arsenal manager Arsene Wenger felt that a defensive reshuffle was behind his side’s loss to Manchester City.
The Emirates Stadium chief thought that an injury to Johann Djourou just after half time was the reason City were able to break the deadlock.
“I feel we suffered from reshuffling our defence completely,” said Wenger.
“We have no full backs at the moment and every injury is difficult to cope with.
“We knew it was vital to have a splendid defensive performance and we had that in the first half. In the second half once we had injuries at the back it was too much.
“Djourou's injury gives us a new problem and unfortunately at the moment there are no solutions.”
Arsenal now have five of their first choice defenders out injured, as Djourou’s groin strain is set to keep him out for three weeks.
Wenger has already been forced to deploy centre-backs across the defence and will now be forced to promote a reserve or youth team player.
The Frenchman was disappointed with the Gunner’s second defeat in Manchester this season, despite an encouraging performance.
“Encouragement is good but it is not enough - we want points,” he added.
“I feel it is frustrating because we had a quality performance with a quality spirit.
"We lacked a little bit of something in the final third and their goalkeeper had a good game.
“Overall it is very disappointing for us to come out with no points. But we have to take the positives out of the game and come back in the next one.
“You could see there was very little between the two teams and the one that could score first certainly had the advantage to win the game.”