The Frenchman was outstanding for the Gunners last season.
"I think I am in the top three (defenders in the league)," he told L'Equipe. "We finished with the best defence. I watch a lot of matches. I am a very humble person but last season, just like this season, I am in the top three defenders.
"I need to continue to work to go even higher. In terms of concentration, I am a lot better. Before, I could play a top match but in one phase of play, I slept a bit. That is no longer the case. I am always on alert."
On being beaten by Manchester City to the Premier League title, he also said: "We played against them three times (last season) and we made them struggle.
"They feel and we feel that we are close to them. Next year, we will have an even better war."