The thing with McStay is that he is the classic "project player" and they tend to be heart breakers and sometimes coach breakers.
McStay started as a forward with limited success, shifted to defence where he quite didn't work out, has now switched forward again and still struggling there.
After 84 games and plenty of opportunity his biggest 'bag' in a single game is 4 goals (against Carlton) and he has kicked 3 goals on only three other occasions. Hardly inspiring stuff. This year he is averaging a goal a game, but he hasn't kicked a goal in 2 out of 5 games.
I'd love to see him come good, but on what we have seen so far, it is not looking promising. I would have said he was worth another shot in defence, but with Walker in career best form, there really isn't a place for McStay in defence.