Rudiger played exactly half PL minutes last season. With him we conceded 10, without him 26 goals. You may argue it is because he started playing under TT in 3atb but remember that also he and Zouma in pairing kept always clean sheets under Lampard who for some reason barely used them together. Rudi did not play in 7 of our 9 PL losses last season. Even under Tuchel that freak game against WBA happened without him. We also argued that Jorginho mistake against Arsenal in home loss would not happened if Rudi was there in Zouma place. So he is very, very important. And now when Zouma leave apart from him we do not have a player who played LCB in 3atb system which makes him even more important. We need him even if that means losing him for free next summer because on this market in this contract situation we cannot get more then 20m.