Any time a player goes from one system to another, one thing...

Any time a player goes from one system to another, one thing that could be a problem is breaking old habits. It's not that you don't understand what the new responsibilities or plays are, but just the fact that you've been doing something a long time - it's a habit - and that's not what's required in the other system. And that means kind of undoing something before you can even start to do something new.