Serious seems like Mangala's staying.. I think he deserves another chance he's physically got it all to be a top class centre back in the premier league, he just needs to Improve on his distribution. I'd rather him than Otamendi IMO
He has got a really long way to go though. Watching him vs. Madrid he looked so out of place on the ball, sometimes just getting in the way, and his touch is heavy and passing selection is not good. The others avoided him deliberately at times.
But he can and will improve, and we know from a passage in Pep Confidential that Pep believes basic technique can be massively improved no matter how old a player is. Rondo's Rondo's Rondo's until he sees crisp one touch passing in his dreams.