What formation / players you struggling against? I had problems with Man City's 4-1-2-2-1 with there AML and AMR. Specifically assigning your LB and RB to them can help a lot, tight mark always and show onto weak foot. Just making sure your full backs cover them by lowering there mentality and forward runs can help to. If its there full backs getting forward and outnumbering your full backs then could man mark with the outside central midfielders to make sure they get out wide.