Ozil released a statement on Wednesday saying he was "deeply disappointed" not to have been included in the 25-man group and believes his loyalty to the club has not been reciprocated.
The 32-year-old is the highest-paid player in Arsenal's history but has now been omitted from both the Premier League and Europa League squads.
"Obviously a player of that dimension, with the career he has had, everything that happens around him has a big impact. It has been the case for the last eight years, it is nothing new that is just happening now. A lot of things have happened over these eight years.
"My job is to get the best out of every player, to contribute to the team performance. Here I feel at the moment, today, that I have failed.
"I want the best possible Mesut for the team. And in some moments I was able to get close to that, and at the moment I have not been able to do it because I have to make the decision to leave him out of the squad."