''If there is a hidden skill that makes that player make lot of fouls, why not a hidden skill that makes that player have more injuries like it happen in real life?''
Unfortunately there is, it is the same hidden aggression stat. Have a look at a couple of aggressive players in close detail and you will notice that there are in fact four aspects to this. They commit more fouls, they draw more fouls, they injure more opponents and they get injured more.
The way the GE is currently coded all injuries come from fouls so it is obvious that players that commit more fouls and are fouled more injure and are injured more, but it seems that they also pump up the severity of the injury.
Lets imagine the first table like this.
According to some aggression is believed to be like stamina and so varies from 1 atrocious (the worst, what lucky fans have) to 9 proficient.
Each play chance of comitting a foul is 10% minus aggression.
Each foul has a chance of becoming an injury equal to 1% minus aggression divided by 10.
The seriousness of each injury is rolled from 1 (most serious out 5 weeks) to 100 (in game injury back next quarter) minus aggression + doctor level x 4.
If the GE is really doing something like this you can see that at every stage the hidden aggression stat is magnifying the chances of a foul, an injury and a serious injury.
I have had a couple of very aggressive players (Sherwin and Palencia) and I can tell you that they do injure a lot of other players but are also frequently injured themselves.