I would suggest being able to set a tactic where you can assign a defender to go after a particular forward and break his legs!
I have just been beaten 9:0 by a team using wing play. All of the goals were scored by the same forward, most of them headers. While I was watching the match I was just thinking wouldn't it be great if one of my defenders just ran after him and chopped him down at his knees. Then, as an added bonus you could watch him being carried off on a stretcher.
Would anyone else like to see this tactic?