I don't see Arsenal as part of the contenders in this season title race. Arsenal should first of all, win EPL before they can start chasing the Champions League title. Barcelona isn't showing too much of quality in them this season. Maybe, I am using the few matches that they have played to judge them but they need to improve their performance if they want to be part of the Champions League contender this season.
This is a valid point as there are stronger European giants in the Champions League and Arsenal not being able to bring home a trophy over past years though registering outstanding performance and consistent gameplay.
Winning the Premier league trophy should come first before considering to win the Champions League and that is definitely no easy fit with the likes of Liverpool, Chelsea, Manchester City, Real Madrid, Barcelona and the rest. Arsenal can be prospective contenders but winning the trophy requires another level of experience entirely.
I have said this before and again that Arsenal football club needs to pay attention to one particular trophy per season, not necessarily the Premier League alone but any of the trophy they found themselves in the competition, it could be Premier league, champions league, FA Cup Carabou Cup, so not necessarily the Premier league. Their situation overtime, ending each season without a major trophy for over a decade plus is a problem as football club.