So? It's still a defensive position and regardless of whether it's at CB or DM, Cahill is still a reactive player and when you've been playing in such manner for years, you're not going to able to turn into the opposite kind of player overnight. Easy to say Cahill needs to do this, he can do that but does he even have the know-how to do a decent job in DM in a big game when he hasn't even always been reliable in his natural position at CB? DYC above certainly pointed out the issues well of playing him in DM.