There are two possible systems for player injuries in Strat-O-Matic Baseball 365. For the vast majority of leagues, the Standard Injury System is in effect, but there is an alternate, optional Super-Advanced Injury System available for certain player sets that may be used on a per-league basis.
Standard Injury System (standard for all sets except Baseball Daily)
All Strat-O-Matic Baseball 365 leagues use the Standard Injury System, with the exception of leagues who have explicitly chosen to play with the new Super-Advanced Injury System.
Super-Advanced Injury System (standard for Baseball Daily)
The Super-Advanced Injury System is an alternate system that's currently available for single season sets from 2015 and later, and Baseball Daily sets from 2018 and later. It is on by default for Baseball Daily leagues unless explicitly turned off on when a new league is created (in which case the Standard Injury System would be used).