Player 1 is serving the ball to a player 1 on the other side of the court.
At the same time player 2 on the other side of the court runs into zone 2.

Player 1 passes the ball to player 2 who is setting the ball for player 1.

After serving player 1 runs in the court to  defend the ball from the player 1 on the opposite side of the court.
Player 1 passes the ball to player 2 who is setting the ball for player 1.

Player who is setting moves in position to defend the ball.
He has to learn to move in position for defense no mater if there is a block or not.