The German playmaker's eight-year stint ended in a sour note after being casted aside by both Unai Emery and Mikel Arteta.
And former Gunners star Monreal has opened up on what it was like during Ozil's final days at the club.
Speaking to FourFourTwo magazine, Monreal said: "Ozil's problem is that he had problems with everyone.
"It ended badly with Wenger, he didn't play the last few games with him, then Emery tried to bring him back and make him our leader.
"To begin with, he gave him a lot of confidence and Mesut played a lot, but the coach understood there were other teammates who were in better condition.
"Ozil was one of the best players in the team, one of the best paid, but they saw he wasn't at the level required."
But things haven't gone as planned for Ozil in Turkey and he was recently dropped from the first-team squad.