Lotsa coaches make the player drill with automatic footwork after the ball is hit. By the kid, he hits the ball, and automatically heads back to center of intersect and splitsteps as his opponent hits HIS ball.
EVERY shot your kid hits needs him to move his feet and body back towards the center of his court.
NO shots are hit without him moving back to cover his opponent's shots.
If he drills this, he will implement this in match play against any opponent, regardless of skill.