The Japanese winger has been a mainstay in the Signal Iduna Park side that has been crowned Bundesliga champions the last two seasons in a row.
The Asian superstar is out of contract in the summer of 2013, and despite the German clubs efforts, is refusing to extend his current deal with Jurgen Klopp’s men.
“I spoke to Shinji and his advisor last week and to date he is not willing to extend his contract,” Dortmund sporting director Michael Zorc told reporters, translated to English by The Sun.
“We have a Plan A and B and we will follow one of them.
“We won’t gamble, but he has a specific career plan and he plans to play in England.
“We have to accept that, even if we don’t find it good.
“Because he now has a certain market value, there is an economic rationality which has to be followed,” he admitted.
United have been linked with a move for Kagawa in the past, who cost a mere €350,000, but is expected to be sold for around the £10 million mark.
By Gareth McKnight