If a courtesy runner gets injured while stealing a base, does the original player F1 need to replace the injured runner?

The correct choice is that any legal substitute may become the courtesy runner if the courtesy runner is injured while stealing a base. This rule provides flexibility for the team, ensuring that they can continue to play without being penalized by losing a base runner due to an injury. It allows for a smooth continuation of the game by permitting a replacement to step in, which is particularly important in maintaining team momentum and strategy during the game.

This scenario acknowledges that the role of a courtesy runner is primarily to enhance play and doesn't necessitate a strict adherence to the original lineup in the event of an injury. By allowing any legal substitute to take over the role of the courtesy runner, the game encourages fairness and maintains the pace of play.