Ilkay Gundogan has made a swift impact at Manchester City, but says he cannot discount the possibility of rejoining Borussia Dortmund further down the line.
The Germany international, 25, completed a switch to City from Dortmund in June, agreeing terms on a four-year contract.
Following knee surgery that saw him miss Euro 2016, Gundogan had to wait until last week to make his City debut - a 4-0 rout of Borussia Monchengladbach in the Champions League.
A first goal followed in Saturday's 4-0 Premier League win over Bournemouth and Gundogan wants to prove himself away from Dortmund before considering any potential return to the Bundesliga.
"If it was the case in the next one or two years, I would probably not be happy about it," he told Sport Bild.
"Because it would probably mean that I have failed or not developed myself.
"If I'm 29 or 30, I do not know if [Dortmund would] still want me. Basically, I would not exclude the possibility, but now I have other big targets."
‘The pure simplicity of the way Slot has managed the squad is probably the biggest thing I could say about him. It’s not broken, so let’s get on with it’: Liverpool legend full of admiration for Jurgen Klopp's successor at Anfield
‘I trained at Spurs and thought they’d give me a chance. But I received a letter thanking me but saying they didn’t think I was good enough – I was gutted’: How Tottenham missed out on signing Wales legend John Toshack
