Eligibility: Courtesy runners may be used for the pitcher and catcher at any time.

The courtesy runner must be a valid substitute listed on the team roster.

The same substitute cannot run for both the pitcher and catcher within the same game.

Roster Batting:

If the team is batting its entire lineup, the courtesy runner will be the player who made the last out at bat.

If the last batter out is unavailable (e.g., the pitcher or catcher), the designated runner will "roll back" through the batting order until a suitable substitute is found.