My take on the Luiz to Bayern situation:
I see many fans saying cash in but i have this question. What genuine world class defender could you get for 40million? PSG just forked out 30million on potential. The market is not great these days. In my opinion Luiz has played some absolutely blinding games at centre back and has improved significantly over the last 12 months or so. Every manager he has played under and there has been some massive names have all played him centre back so they must know what they are talking about. Does he go walkabout at times yes but that for me could be a very good thing if we play a decent holding midfielder (something Rafa didn't do because he never liked Mikel). Luiz coming out of defence gives us something different at times, strikers have to think whether they should follow him, centre midfielders the same and because of this our players will find space. BUT!!!! This can only happen if we have someone who has the discipline to recognize Luiz has gone and knows instantly "well i have to sit at centre back until he is back". Mikel does that immensely, Essien could do it too.