Jerome Boateng will be allowed to leave Bayern Munich for the right price, according to the club's CEO, Karl-Heinz Rummenigge.
The Germany international admitted he was considering his future at the Allianz Arena back in April after he had 'experienced everything' in his seven years at the club.
It was revealed United are monitoring Boateng's situation and the 29-year-old is one of eight centre-backs on their radar as they prioritise a move for a quality defender this summer.
Boateng still has two years left on his current deal with Bayern, but Rummenigge has refused to rule out a summer sale.
"If a club comes to us and he says that he wants to join that club, then we will negotiate. But the offer has to be important," he told Bild.
After just a season at City, Boateng joined Bayern in 2011 and has gone on to win 14 trophies with the Bundesliga giants.
And Boateng, who is one of two footballers represented by Roc Nation sports agency alongside Romelu Lukaku, is considering his next step.
"I've experienced everything at FC Bayern, and I am slowly coming to a point where I must answer myself certain questions," he previously told Socrates magazine.
"What are the goals I have not reached yet? Do I, time and time again, want to prove myself at the same club with the same pre-conditions?