Final answer:
In volleyball, if a back-row player is replaced during a match, the replacement player must enter the game from the same position, through the service zone, and adhere to the rotation rules.
Step-by-step explanation:
In volleyball, if a back-row player is replaced during a match, there are certain rules that apply. The replacement player must enter the game from the same position as the player being replaced. This means that if the back-row player being replaced is a middle back, the replacement player must also be a middle back.
Additionally, the replacement player must enter the game through the service zone. They cannot enter from the sidelines or any other area of the court.
Furthermore, the replacement player must adhere to the rotation rules. This means that they must take the correct position in the rotation order and cannot enter the game out of turn.