I never use hard tackling.
My first team never trains more than once per day, and its always light - normal training.
In the past week, I have noticed a sharp increase in yellow and red cards, as well as injuries.
My Theory: Nordeus has an algorithm, that scans to see what packs a player has an abundance of, then decides to attack it.
e.g Hmmm, this guy has 250 red packs, that is too much. Boys! Lets afflict him with lots of injuries till he has no red packs left.
Same thing happening to morale.