I'm not playing with the fatigue, it seems to need some fine tuning to be really useful or relevant.
My goaler (with a stamina rating of 20, though) drop at a FIT of 60 after a game as soon as he have at least an appearance in the game, and have a fitness of 94-95 on the next day. With these number, I can make him play every games since he's technically never exhausted. I'm just not doing it just in case of injuries but not based on fatigue/fitness.
After a game, based on the stamina level of course, the goaler who played 46 minutes and received 50 shots should have a fewer FIT than the one who played 14 minutes and received only 1 shot. It seems to be automatically 60 for a goaler.
Also, It should have an impact on injuries, but on player abilities also. A player with 60-80 of FIT may be way less efficient than well rested equivalent player with 100 fo FIT. I don't feel that at all in the game.
Also, based on my IRL experience with dispatch systems analytics, I have an idea about travel penalties logics based on Cities if you are interrested to try to bring the fatigue/fitness to a new level
