To be honest, I am also getting worried about his contract situation. I really hope he has good people around him who would advise him to do the sensible thing and extend his contract with us. We need to get this sorted before the end of the summer otherwise I'd reluctantly sell. It would be daft to let this drag on into the final year of his contract, we'd be forced to either offer him obscene wages, ala Ozil, or risk losing him for free.
Obviously it would be a big blow to lose such a talented CB but France seems to be churning out quality CBs at an impressive rate, so that's where we should be looking for a replacement. I remember Badiashile catching my eye in the France vs Austria match some time last year and I made the effort to watch 2 or 3 Monaco matches afterwards to see what he was about, but was left far more impressed with his CB partner Axel Disasi. He looked the more accomplished defender (tbf he's couple of years older).
He (Disasi) is a no nonsense CB, good man marker, doesn't panic on the ball, has good passing skills and is a threat on set pieces. He played RB for France at the WC, so that shows he's also versatile. Obviously the sample space is very small, but he's just one of the many CBs from France we could take a close look at.