I wonder how well Clark will be able to perform at AFL, even taking his issues aside. He has hardly played much football in recent years:
2014: No games
2013: 4 games at the start of the year, so his last match was rd 4, 21st of April. Hence by Round 1 next year it will have been 23 months since his last game.
2012: 11 games in the first half of the season until rd 13. Hence in the last 2.5 seasons he has played just 4 games.
2011: 17 games, this was his last close to full year he has played.
That is a lot of football missed and the game changes rapidly. I wouldn't be expecting great things from him, especially early days.