By sell, I mean quckfire sale for 20M to RM given they dont have sufficient RB cover or that long ball option that Kroos provided. But you are right, a club like RM will take him for free but not want to pay a transfer fee. They know RBs and LBs should be low to zero cost options.Sell him to who?
There's no way he's going to move in the Jan window. Even if we tried to force him out, he'd simply say no and he'd happily sit in the reserves for 6 months and go and play for Real on a free then. And we lose a RB option for the rest of the season.
Unfortunately, we've lost all leverage in the situation. The time to sell him was in the summer, or last Jan.