Shake should reset mentally and just start with basics. Focus on his shooting, less on trying to expand his game until the offseason where he can have more time to do that. I think it will be easy for him to bounce back from his funk that way.
My guess is that he was also expecting to start after his performance last season specially in the playoffs and what he has done during the offseason, then things didnt fall into place. I dont know him personally and im again saying its just a guess, but I think that affected him personally.
We have Maxey and GHill now as guards off the bench who can play with him, so no need to focus more on creating off the dribble. Start with the basics, just knocking 3s and playing defense.
“If anyone can refute me—show me I'm making a mistake or looking at things from the wrong perspective—I'll gladly change. It's the truth I'm after, and the truth never harmed anyone." Marcus Aurelius.