box.
Injuries Y/N for the user to determine.
Maybe have three levels of injuries that the user determines. Also a career ending injury. Again as an option. I do this using random numbers. My previous FAB champ suddenly retired on the last aging check I did, a 100 came up.

Auto scheduling...I like the scheduler to check the current month. For example Ali fights Louis and then I auto schedule the rest of the heavies based on 60 days off and Ali and Louis will be assigned fights, the scheduler doesn't see the fight for that month they had.
Option again, rest... for example Tyson early on fought 2 fights a month in some cases, maybe a fatigue factor based on X days between fights. Maybe different levels again.. 1 to 5. 1 very fatigued to 5 tip top shape.