Arsène Wenger agrees that Arsenal must tighten up at the back against their biggest rivals - but he thinks last season's defeat at Manchester City was not as damaging as the scoreline suggests.

The Gunners went down 6-3 at the Etihad Stadium in December but they were in the game for long periods before a flurry of late goals added gloss to the scoreline.

Heavy defeats at Liverpool and Chelsea later in the season were more one-sided and Wenger knows that greater resilience in those fixtures will be required this season.

I was concerned and shocked by the number of goals that we conceded

"I was concerned [by Arsenal's record against the top four]," admitted Wenger. "I was concerned and shocked by the number of goals that we conceded. Of course we were Dr Jekyll and Mr Hyde defensively. We had 18 clean sheets but when we did not keep a clean sheet we let them score.

"I think it was down to confidence. Overall we were quite sound defensively but we have a good opportunity to improve that.

"Honestly [the Man City game was] not so much damaging because we finished with 10 men and when we looked at the game again we had six or seven chances to score," added Wenger.

"I took a gamble at 10 against 11 like I always do to have a chance to come back, but when you look at the chances we missed, that was not a damaging [result]. For us what was damaging was the two games at Liverpool and at Chelsea.

"With City we came home and felt that we played Wednesday night in Naples and then Saturday morning at Man City and we had plenty of chances. We were not outplayed, we lost the game in the last 20 minutes really."

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source Chris Harris 7 Aug 2014