Yeah it's a concern. After the first 6 games I thought he was way out of his depth, of course he turned it round and for a while we were genuinely good, some great results and good to watch. However the last few months have been appalling, some of that is down to injuries/burnout of course but thats where a coach earns his corn, he simply has to mitigate the loss of players with tactics and set up that get the most from what he has. If the players can't do what he asks then he simply has to change something, which he hasn't.
It seems churlish to be calling for his head currently but if he gets some signings that he wants, then he won't or shouldn't get too much time next season if we carry on with our current trajectory