Per Mertesacker, the manager of the Arsenal Academy, described his former team-mate Mesut Ozil as a "genius", but insisted it was up to him to take his game to another level.
Ozil was out of season for Unai Emery as he missed the opening game against Newcastle for safety reasons before being banned from illness by Burnley and Liverpool.
The 30-year-old was inducted into Arsenal's North London derby squad, but failed when Emery turned from substitute bench to playmate Dani Ceballos instead.
Ozil has undoubtedly demonstrated his qualities during his six-year tenure at Arsenal, but was accused by followers of not agreeing consistently with his form.
When asked if he understands the frustration of the Arsenal fans with Ozil, Mertesacker replied, "Yes, because they probably do not understand him.
"I know how to take him and how to try to pinch him when needed. But in the end it has to come from him if he wants to go to the next level. But he can deliver.
"He likes playing football, it's not that common, he's a genius of what he can do with the ball, and you can see that in every training session.
"He thinks he plays in the park, he can deliver the ball that nobody else can deliver. He has this magical sense. "
Ozil was virtually ubiquitous during the time of Arsene Wenger, but he was faced with Emery's plans during the Spaniard's responsible debut campaign.
Emery often played a bench in Ozil last season, scoring just five goals and two assists in 24 Premier League games, with the latter statistic his worst return in English football.
Mertesacker was a longtime teammate of Ozil for both Arsenal and internationally with Germany, and admitted that it took some time for him to understand his character.
He added, "He wants to be okay with everyone. He's not the type who approaches people and says, "You have to do this, that and that."
"He's a different character, and sometimes I had to fight with it."
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