Mourinho worked with the Germany international for three years at Real Madrid, having signed him from Werder Bremen in 2010.
Ozil made the switch to the Premier League a year ago when he joined the Gunners for a club-record £42.5million and went on to help them claim the FA Cup in May.
However, the 25-year-old came under fire for his performances and apparent lack of commitment during the latter stages of the 2013/14 campaign, while he also received criticism from Die Mannschaft fans recently.
Mourinho admits Ozil is a special talent but revealed he is a confidence player and needs the faith of those around him to truly shine.
The Portuguese mentor said: “I think it’s hard to criticise him. Ozil is Ozil. If you were expecting Ozil to be super aggressive and to be running miles and miles from side to side and to show great enthusiasm and aggressiveness, this is not Mesut.
“If you are waiting for somebody where every time he touches the ball, the ball smiles, every time he makes a pass, the ball goes with the right direction, the right speed, the right intensity, this is Ozil.
“I learned with him because we were together for quite a long time, that he’s a very sensitive boy. He needs confidence. He needs trust. He needs to feel that people is with him. When he’s on the pitch, every time he touches the ball, the ball goes beautiful.
“And he’ll always find the right man on the right place. So, sometimes, you don’t see him, sometimes he doesn’t go to screen many, many times. But when he goes he is a special player.”