The defensive player has switched to guard a player who does not have the ball. Therefore, the switching player must assume a position one or two strides in advance of the post player (depending upon the speed of movement of such player) to make the action legal. If the defensive player moves into the path of the post player A1 after A1 has control of the ball (provided the post player is not in the air at the time), the play becomes a guarding situation on a player with the ball and no distance or time limit is involved.