The Germany international began his professional career at the Bundesliga outfit before switching to Werder Bremen at the age of 19.
After progressing further there, Madrid swooped in 2010 as Ozil spent three years at the Bernabeu.
Since then, he has become an integral figure in Arsenal's team, although his future is still in doubt.
The 28-year-old is yet to come to an agreement over a new contract with only 12 months remaining on Ozil's current deal.
Few clubs have shown an interest compared to Gunners team-mate Alexis Sanchez, who is in similar position.
Mesut Ozil has one year left at Arsenal with his future up in the air
Schalke is my absolute favourite club, I’m still a big fan
However, while Ozil is not pushing to leave Arsene Wenger's side, he has admitted his heart lies elsewhere.
"Schalke is my absolute favourite club, I’m still a big fan," Ozil told Funke Media Group.
"After all, I grew up with Schalke.
"In terms of potential, Schalke is the number three for me in Germany after Bayern Munich and Borussia Dortmund.
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‘The fact he always looked controlled’
"They have wonderful fans and a great stadium. It is a pity that they are stuck in mediocrity. This fantastic club deserves more."
Dropping a hint over his future career path, Ozil added: "My family would be very happy about a return."
The playmaker has been offered a new contract with a substantial pay rise.
But as things stand, Ozil could still leave Arsenal this summer with the club facing losing him for free in 2018.