Mertesacker believes that Arsenal are reaping the rewards of keeping a largely settled squad intact during the close season, with the emphasis now on sticking together through a long campaign.
He told The Guardian: "Our game hasn't changed, it's more that [Ozil] fits into it. His progress is quite well at the moment and I think he will show more and more during the season. You can expect a lot from him.
"We have a few blocs. We have a French bloc, a Spanish bloc, a British bloc and a German bloc, so we are international-influenced and that is what Arsenal is all about. It's now about sticking together as good as possible and as much as possible.
"Arsenal wants to play international football and, when every player fits into that game, we can be successful. It's hard to say what is different but I think one point is that we didn't lose any player from last season. It was always a bit hard when we lost [Robin] Van Persie and Alex Song last season, but we kept the squad [this summer] and there is more quality to come."
Arsenal return to action tomorrow afternoon at the Emirates, with Norwich City the visitors to North London.