In my Level 8 League this season there has been 42 matches, in total 22 injuries. The most injuries was in R2 with 8, the least in R1 with 1, the most in any one game was 3. Not an exorbitant number overall I would have thought. Maybe I'm just in the right League on the right server.
I wonder if the string of inuries being reported on the forum this season stem from lower level leagues where managers are less experienced, pitches are of a lower standard etc etc.