Defensive mistakes contributed to both of Southampton's goals, but Wenger has insisted that it was his side's attacking incompetence which saw them knocked out of the competition as they failed to convert their dominance of possession onto the scoresheet.
"We are a bit short, yes, because of the injuries we have," he told reporters. "You sit there and think: [Kieran] Gibbs had a little hamstring problem and we could not play him, [Per] Mertesacker is a bit on the edge, and then we have no choice.
"I think if we lost the game tonight, it's not because of Hayden, not because of Chambers and not because of Coquelin. You have to be realistic. I don't want to go into any individual assessment, it's always very easy after a defeat. We gave a lot, I cannot fault the spirit, the attitude.
"The first reason for our defeat is the quality of our opponent and the performance of our opponent. And the fact that we couldn't score. We scored on a free kick, apart from that we couldn't score. The amount of possession we had second half, if you play at home with that much possession, you have to score."
Arsenal's defence at the Emirates Stadium had made 54 first-team appearances for the club between them, with 43 of those being made by Coquelin, who is primarily a midfielder.