The midfielder lifted the Champions League trophy after a 1-0 win over Inter Milan on Saturday night, completing a historic treble.
The 32-year-old has been a crucial player in Man City's remarkable campaign, with focus now turning to his contract situation.
Gundogan may have played his final game with his current deal expiring this month, leading to interest from Arsenal, Barcelona and Borussia Dortmund.
But the German did not confirm a departure after the Champions League triumph. He told ESPN: "I haven't decided my future yet."
Per Mertersacker, who is now the head of Arsenal's academy, believes that victory in Europe's biggest competition could pave the way for a move to north London.
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Speaking as a pundit for German broadcaster ZDF, Mertersacker speculated that victory in the Champions League could lead Gundogan to say: 'okay, mission accomplished'.
He then added: "I think the clubs are queuing.
"Because [Mikel] Arteta knows him and we probably haven't broken off contact, we're in a good position.
"I think he'll let it all sink in first and then choose from one of the four clubs."