Back in PES days, I remember screaming to my mates (multiplayer co-op), “defend with midfielders”. That’s a great tactic. Don’t disturb your defensive organisation. Chase down the opponents with your midfielders and tackle them, if need be. In worst case, it’s you midfielder who might get sent off and not a defender which is a more specialist position. In other words, use your defenders as the last resort. This would also mean trying to nip the attacks in the bud, instead of preparing for a head-on collision as a defender. Especially when you want to apply pressure, don’t do it with the defenders, because just one quick piece of skill would leave your defender biting the grass and your opponent could be straight on goal. The mantra is “defend with midfielders”.
Check here for a full article on art of defending in FIFA 09.