Arsenal defender Per Mertesacker says they must improve in attack after defeat at Chelsea.
The German was pleased with the performance of the Gunners defence on the day.
Asked where they fell short, Mertesacker replied: "In the final third. I think we defended quite well. There was always a cover and there was always protection in the final third. We had a couple of decent chances to get through but we failed with the last pass or the last touch.
"We were much more competitive and we defended much better. That's what we can take. But they were still better and we have to learn quickly."
