If he does leave that’s an utter disaster.
We have to plan for the time when him leaving won't be a disaster.
Any responsible owner will be doing this as a part of regular contingency-planning.
My guess is that Nas n' Wes will have a priority-list of replacements (Iraola and Glasner would be near the top of that list, I'm guessing); not that they'd have approached anyone, of course.
The bigger challenge might be replacing all those whom Emery has brought in specifically to work with him; not in terms of finding people but getting them in in a timely fashion. And, what Damian decides to do might well be significant, too.
