I agree with that completely - but man-marking is nothing new and if a player is being marked out of a game (like Duff was so comprehensively against France for example) then something needs to change. Switch wings, move into the middle ... just vary things to try and get the talented players like Duff more involved. When he was at Chelsea (and in the team!) him and Robben would often switch wings when things weren't working. I don't know if this is down to Duff, or to the manager, or to the captain but someone needs to recognise when things aren't working during a match and change things round.