Arsenal defender Per Mertesacker admits they struggled last season after the departures of Alex Song and Robin van Persie.
The Gunners are currently top of the table.
"It's hard to say [why Arsenal have started so well]," Mertesacker said. "I think one point is that we didn't lose any players from last season. It was always a bit hard when we lost Van Persie and Alex Song last season. The year before, we lost Nasri and Fabregas. We kept the squad [this summer] and now I think there's more quality to come. We have a few injured players as well, we hope they are coming back soon."
