I am getting killed when the computer gets a corner kick. I've tried using my controlled player to mark on one of the chosen attacking players ("A", "W", "D") and even sticking him in the goal to try to stop the AI from heading in goals without success. The computer is scoring at will on corner kicks (I play at the professional level). Any ideas? Thanks.

you can't stop the computer from scoring at corners. it depends on the heading skill of the attacker and the defender. my way of defending corner kicks is right after the computer has taken the corner, i press and hold shoot and hope for the best....