I have said this for years, and got slated by my mates for saying it, so am expecting an onslaught here too!
Stevie has been as much of a problem for us as he has been our saviour.....(stand back and wait for the beatings!)
Here's why. He has no clearly defined position, and when put in a position he will go wherever he wants or feels he can do damage. This is fine if you are in a team full of quality, where its not going to matter much, because other players are good enough to cover for you, but he has not been in a team like that realistically since Benitez 2008/9.
Even Benitez would play him wide right, to try and minimise the impact of him going missing from the centre but still give him an attacking role.
For England he has been played all over the place, because he hasn't been able to clearly define a position that he "owns" and nobody can shake him from.
Playing him with Lucas, and having him hold his position a little more is a lesson for Stevie, but at certain moments he throws it out the window, and goes all Roy of the Rovers on us.
Recall Rafa subbing him in a derby? "Sometimes you have to play with your head not your heart."
Don't get me wrong I love Stevie, and would happily argue that he is one of the greatest players ever to wear the shirt, but his lack of positional certainty has been a problem.