Aggressiveness is a hidden attribute in BB(what most people think). Theres nothing you can do about it, before buying someone make sure hes not getting 4 or more fouls frequently, because more often than not he is probably an aggressive player like this one.
I would try to sell him pretty soon because he wont stop fouling out.
I also have massagist to make him relax a bit (yeah, i know that doesnt work :D )
I wish there was a therapy or something in this game to calm them down. Or maybe a translator or something to communicate and let them know that Basketball and Hockey aren't the same.