Arsenal could yet finish outside of the top four this season.
The Gunners have impressed with their start to the campaign and top the league with just under half the season gone.
However, signs in recent weeks show Arsene Wenger's side are far from guaranteed anything from their good start.
Despite doing well to qualify from the most difficult Champions League group, a defeat to Napoli means they could face one of Europe's elite after finishing second.
Allied to the unlikeliness of Champions League success, their fine start domestically sees them just a couple of defeats away from sliding out of the top four.
And with tough London derbies in their next two fixtures, by the end of Boxing Day Arsenal could have dropped from champions elect to Champions League hopefuls.
Should Arsenal fail to defeat Chelsea it will be four games without a win - not the sort of form title challengers should be providing.
In recent seasons the Gunners have started poorly before clawing their way back into the top four.
In each of the last two seasons Arsenal have closed big gaps on rivals Tottenham, and it is far from ridiculous to suggest that the shoe could be on the other foot this season.
Arsenal will need the likes of Olivier Giroud, Mesut Ozil and Santi Cazorla to re-capture their form or their title challenge could be over before it really began.
It wouldn't be the first time the Gunners have collapsed after a bright start - 2008 should serve as a warning to Wenger at how quickly a side can slide from the Premier League summit.
Write for GiveMeSport! Sign-up to the GMS Writing Academy here: http://gms.to/1a2u3KU