Zinchenko was nowhere near this bad last season, and if it was just him, then I would cede that it's a Zinchenko problem. Unfortunately, Martinelli is stinking it up just as badly and Trossard seems hellbent in joining the group. Xhaka was the lynchpin to that side of the pitch and without him it's all broken down. People have these nonsensical notions of mythical footballers who can do it all, hence why you had this season-long narrative that any decent midfielder would upgrade on Xhaka. Someone who can defend and protect the defence, who can pass and create, and also attack and score goals. LOL, like there are midfielders like that just waiting for Mik's call. With all the midfielders that moved in the PL this season, there isn't anyone who would have upgraded Xhaka and with all of them there are trade-offs.