Arsene Wenger's side have returned from a tour of Asia with a 100 per cent winning record including a 2-1 success over Japanese outfit Urawa Reds on Friday.
Arsenal continue their pre-season campaign by hosting the Emirates Cup, which takes place this weekend and features Porto, Napoli and Galatasaray, before a fixture with Manchester City on August 10 in Helsinki.
France international Koscielny is happy with the team's preparations and believes the squad are in good shape ahead of their opening fixture against Aston Villa.
"We won all our games so that's good confidence," he told the club's official website.
"We had a lot of training and all the players trained very well and gave themselves for the team.
"Pre-season is very important for the Premier League. It's a long season so we need to be fit - I think we did well.
"The win gives us some confidence, and it's good for the next games - the Emirates Cup, (the friendly) against Manchester City and the start of the season."
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