The goalkeeper stands on the goal line.
The coach is holding 2 balls.
The first ball is thrown in a high and soft arc in the direction of one of the poles.
The goalkeeper jumps, and catches the ball and places it on the floor in front.
At that moment the coach throws the other ball directly at goal.
The goalkeeper must try to block.
The coach adjusts the speed and placement of the balls in accordance with the skill and reaction ability of the goalkeeper.