Remember though that Madden IR only includes players who are "out". There is no "questionable" or "doubtful" players: in Madden, they are in or out. You don't have those Aaron Rodgers, questionnable but playing the game, or what we saw for years with Tom Brady (always "probable" but of course he played and was 100%). So keep that in mind when doing comparisons.
For week 3 in the NFL, we have "only" 62 players out, 10 "doubtful" and 77 "questionable". 149 players. Half of them were 50-50 (the "questionable"), so let's say half of them played and all "doubtful" didn't: we have 110 players out. 3-4 by team. That's the average number we should aim.
http://www.nfl.com/injuries
And of course, nobody is injured during practice in Madden.
I'd like to add that in my opinion, another great thing with this Madden 19 is that no key injury makes a team "dysfunctional". Key players are great, make a difference, but you can have a quite efficient offensive line to play with or against, even with a pair of 70 players. Some sub QB or RB can still damage your D, even if less regularly than starters. So we shouldn't be affraid of having injuries, in this edition it's really "just part of the game".
God I love this game.