I'm just saying... players don't just train on what a Coach wants. After practice they practice/play/train on what ever they want, to improve their own game. That's real life.
So take these pops as the guy doing extra work on his own.
No one in their right mind would have told Shaq "You've really got to stop working on those stupid Free Throws after practice! I keep telling you, Inside Defense, Shot Blocking, Rebounding! Stop with the Free Throws and Passing after Practice! No more!"
Sure, it messes with your final master plan... that's life. That's how it REALLY WORKS. So be a good manager (not that I am a good manager yet) and learn to adapt to this.