Wait, you are seriously making a case that you can divide his minutes but his games and provide an accurate representation of being given an opportunity. Regardless of what you think of VdB, I thought i had seen every bad take on the caf but here's a new one:
Player A plays 90mins, 90mins, 10min, 10min, 10min, 10min, 10min, 10min, 10min, 10min across a series of 10 games.
Now 10 games is a decent amount to look for trends and he's played in all of them. So with your forumla he's played 260mins across 10 games which equals 26 minutes a game and plenty of time to see what he's about?