The central midfielder has long been linked with a transfer to the Premier League, with United and Arsenal both touted as possible destinations for the 24-year-old.
Gundogan, who signed a two-year contract extension back in April, has recently confirmed that he plans to stay at Dortmund for at least another year – but the midfielder says that he could leave the Bundesliga club next summer.
Gundogan told Kicker, as reported by talkSPORT: “For me it was always clear that all sides must benefit from it [a move away from Dortmund].
“I cannot say this will never happen; maybe in a year, maybe in two years.
“But a departure in the winter is not on the table.”
Gundogan, who joined Dortmund from Nuremberg in 2011 and has won the Bundesliga and the German Cup, has made 26 appearances for Dortmund this season.
The Red Devils have already signed highly-rated PSV Eindhoven forward Memphis Depay in a reported £25m deal back in May.
Manchester United kick off their Premier League campaign with a home clash against Tottenham Hotspur on 8 August.
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