3D AF not the best option for soccer

This photo from an Under-11s soccer match was shot with my D600 and Nikon 80-200 f./2.8 using the 3D Auto-focus.

The picture shows my grandson (in blue with the ball) reacting to the referee's whistle having just been caught offside.

You can see that the focus is not where I would have wanted it. Straightforward user-error. Wrong choice of AF mode.

But the body language of my grandson's team-mate ensures it's a keeper!