This guy's really rocking some deep trauma from his Chelsea stint, someone get him a copy of THE BODY KEEPS THE SCORE …
Something Wenger was good at (or at least something Wenger made a virtue out of) was ensuring a player who was psyching himself out of form understood Wenger would just keep playing him, that he couldn't get out of being on the pitch just by freaking out, and that freaking out wouldn't get him abandoned or discarded in a hurry.
Once the only consequence left is going out and looking a bit like a donkey week by week, some of the guys who get into the sort of headspace Havertz seems to be in will finally pull their fingers out and stop self-sabotaging.
It'll be interesting to see how far Arteta can back himself here, as Havertz is his project.