Ozil has been omitted from the Gunners' Premier League and Europa League squads and it appears unlikely he will ever feature for the club again.
"What I can tell you that I tried my best, I tried to give him as many opportunities as I could," the Arsenal boss told Sky Sports.
"And that from my own side, I've been patient, given him opportunities and been fair.
"He's a player that belongs to a football club, he's been a really important player in the last few seasons. I have to respect that, I'm here to make decisions, the best decisions for the team and for the club.
"This is what I try to do and then I have to explain them because people need the reasons and the right answers. I just give mine, whether they believe me or agree with me or not, there's nothing I can do.
"But I have to put my decisions, with my heart and with my brain to make the right decisions that I believe are good."