Fatigue

How does the whole fatigue thing work?
This always was something I really never understood that much.
I've always just had the values around 40 - 50 for most positions excluding QB and Kickers.

Like once a player gets pulled out due to "fatigue" is their fatigue level going to decrease as they sit out? Do they come back in the game or are they done?

QB and kickers, I set at 100, the rest anywhere between 42-55 depending on depth.

I did a search of the forums and found this discussion:

https://usflwfl.myfootballnow.com/community/3/3981?page=1#25824