The effective ratings are reduced based upon the severity of the injury, but we have been told it isn't as simple as a straight multiplication of the rating by the percentage of health the kid currently has.
I'll work a kid back into playing rotation for spot minutes in the low 80s. Depending on how much better the kid is, I'll restart them around 90. I had a kid that I'd promised a start to one season get knocked down pretty low, but I'd already sat him for some key conference games so ended up having to start him at 68...I expected him to perform like a walk-on, but it wasn't as bad as I'd predicted and we were able to win games while he was limping along.