What must the referee do if a player commits an offense while off the field during normal play?

When a player commits an offense while off the field during normal play, the correct course of action is to stop play, address the incident, and restart with a free kick on the boundary line. This procedure is crucial because the referee needs to ensure that any foul play or misconduct is appropriately addressed, even if the player is not currently on the field of play.

Stopping the game allows the referee to manage the situation effectively by potentially cautioning or dismissing the offending player, depending on the severity of the offense. Restarting the match with a free kick on the boundary line ensures that the game resumes fairly, while also maintaining the flow of play.

The other options do not align with the established protocols. Allowing play to continue does not address the offense committed, while restarting with a goal kick would only be appropriate in specific circumstances related to the ball going out of play. Issuing a red card without stopping play first and making an appropriate assessment of the situation would not comply with the rules governing officiating conduct. Therefore, stopping play and addressing the incident followed by a free kick is the standardized approach in such scenarios.