Gallas said: “I don’t know exactly what has happened but something has changed within the club this summer.
“Opponents will not be able to kick Arsenal any more. We are ready to give our answer to that sort of thing.
“Our players now understand how they have to play at certain times. We know we can always score at any time because we have so much quality up front.
“But now we also realise we have to fight, to be compact and defend very well. All the players have benefited from the experience of last year and understand the demands of football in the Premier League.
“Sometimes it is not enough just to play good football when the other team is hitting long balls all the time.
“We have to be ready to fight and I think this season we can be physical enough to deal with that side of the game.”