The Japanese playmaker only arrived at Old Trafford from Borussia Dortmund last year, but has struggled to hold down a first-team spot under Sir Alex Ferguson and now manager David Moyes.
Kagawa himself is believed to have grown frustrated with his current situation, while his manager is thought to be unconvinced by his abilities.
This has opened the door for a move away from the premier League champions, with his former club leading the queue for the Asian ace’s signature.
Dortmund are said to have the funds in place to push through a move for their one time icon, and fans of the club have already voiced their desire to see him back in the yellow jersey.
United are reportedly willing to sell the 24-year-old for the right price, with Moyes keen to free up space for additions to his squad.
Kagawa has featured just 37 times for his current side and has often been deployed in a wide position, despite being a central player by trade.
Hailed as one of Europe’s top creative talents prior to the move, the playmaker is likely to be tempted by the opportunity to get his career back on track.