Theoretically, players who are highly agressive should not only foul more but get more fouled. It could be nice to have a player drawing lots of fould, if not for two things: These players are so hard to train that it is improbable that he can reach a high level in skills (in comparison to a equal player with less agression) and the fact that it appears that injuries in this game are a random chance every time a player is fouled. If he is constantly fouled he has a bigger chance of injury which will further hinder the training. (Dont quote me on this, tough. I dont think any GM has confirmed that injuries happens ramdonly with a chance on each foul - it just appears to me that thats the way the game is)
I am with everyone who told you to sell this player ASAP. I gave up on training for a season because of one trainee like this. It screwed his training and my other trainees were not that great and I lost all motivation for training.
So, to avoid frustrations, drop this guy and better luck in your next trainee.