Sounds like Simmons will not be playing in Thursday’s game. What a shame... 
If you were expecting to see Ben Simmons soon after the end of the All-Star Break, you should lower your expectations. ESPN’s Ramona Shelburne who has excellent sources in Simmons camp, says the newest Net isn’t likely to play for “weeks.” Here’s what she said on ESPN’s NBA Today Monday… “Ben Simmons, from what I’m told, is going to really ramp it up this week and see where he’s at at the end of the week, but he’s getting close. I don’t think it’s going to–it’s going to be more like weeks rather than months.” via Net Income @ NetsDaily
Now this lends more credence he is actually fighting a mental illness. I retract my former criticism, as I said I would, if he showed the actions of someone actually struggling with mental illness.
As I said then, there was no way he could snap his fingers and be ready to play if he had mental health issues. Changes of scenery don't suddenly change that anxiety and it appears to be playing out here.
I am sorry for misjudging you Ben. Please, get the help you need and return when you are truly healthy enough to return.