The German defender has stated that his team have lost too many games in recent seasons to be champions.
The North London side played some devastating football last season but ultimately fell short in their ambitions of becoming English champions due to inconsistent periods in the campaign.
Arsene Wenger’s men lost their first game of this season at home to West Ham this time round, with the Hammers surprisingly picking up a 2-0 win at the Emirates Stadium.
Mertesacker has used Chelsea as an example and stated that if the North London outfit want to be top dogs this season they can only afford to lose a couple more matches.
“If you compare us to Chelsea, the reigning champions, I think they lost only three games last season,” the World Cup winning German told The Guardian.
“That’s something we haven’t been able to do. We lost six, seven or eight games per season, that’s not good enough to win a championship.”
Arsenal will be tested in their next clash, as Liverpool are the visitors to the Emirates Stadium on Monday night.
The Gunners beat the Merseysiders 4-1 in the equivalent fixture late last season and will hope to replicate this performance and result.
Wenger’s men got back on track last Sunday with a 2-1 away win against Alan Pardew’s Crystal Palace side at Selhurst Park.
Chelsea have started the campaign slowly and have only picked up one point from their first two games, meaning that the race for the title this season looks to be wide open.