(AN: I seem to be breaking a lot of the bad news around these parts recently. Please don't shoot the messenger.)
The official Borussia Dortmund Twitter page just shared this:
A quick translation (courtesy of my German office roommate):
Bad news for Neven Subotic. An examination by a specialist in England has uncovered that the Borussia Dortmund center-back needs surgery in his rib-cage. It is predicted that Subotic will be out for the rest of the year. The defender will not be switching teams in this transfer period either.
This really is terrible news for Neven. He was looking forward to moving clubs this transfer season, but it's all off the table now. Whatever this issue is, it was probably discovered during a medical at Middlesbrough, whom he had been rumored to be close to joining.
I hope his recovery and rehab go well and this isn't the end of his career. He's been an integral part of the club for so long, he deserves to leave us on a high.
Gute besserung Neven!