Per Mertesacker claims Arsenal's lack of quality in the final third saw them suffer a defeat at the hands of Chelsea on Sunday.
Eden Hazard converted from the spot kick in the first half before Diego Costa doubled the lead in the final quarter of the match. The Gunners had summer signings Alexis Sanchez, Danny Welbeck and Mesut Ozil to lead their attacking lineup. Mertesacker claimed the north London side were not good enough to score a goal.
Last season, the Emirates club suffered a 6-0 defeat against Chelsea at Stamford Bridge. This campaign, the Gunners were more equipped and their manager Arsene Wenger admitted his side had more chances, but were unsuccessful in converting any of them.
However, the German international had some positives to take from the game and was delighted with Arsenal's defensive performance.
"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," Mertesacker told Arsenal's official website.
"Obviously we were more competitive this year. That was the first target, to be much better than last year. At times we were good but not good enough to score a goal."
"Defensively we made two wrong decisions and we missed the final touch in the last third and the final ball - that was the difference. Overall we have to admit that we can take some positives out of this game but there's still something to do."
"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," the German centre-back added.
The defeat saw Arsenal end their unbeaten run in the Premier League. They now sit eighth in the table with 10 points after seven matches and are one point behind fourth place Manchester United.