This is starting to bug me too. Every injury I have seen has been long-term too...don't get my wrong, I like it for challenge...but it becomes a problem for the CPU in roster management. It seems (based on small sample size) to be worse since I adjusted the MM injury slider. New this year, EA set it to 10. I thought it was a mistake....now I am starting to wonder.
I have a sneaking hunch that the MM slider could be serving as a "injury severity" slider. That's going to take some sample size to prove/disprove.