When a courtesy runner is injured while on the bases, what are the possibilities for replacing him? Can he later return as a player if replaced? Who can or can't replace him as the courtesy runner? A reference to the rule book would be helpful.

Thanks

FED Speed Up Rule Page 61 2006 Rule book

COURTESY RUNNERS
1. At any time, the team at bat may use courtesy runners for the pitcher and/or the catcher.

2. The same individual runner may not be used for both positions (pitcher and catcher) during the game.

3. Neither the pitcher nor the catcher will be required to leave the game under such circumstances.

4. Players who have participated in the game in any other capacity are ineligible to serve as courtesy runners.

5. A player may not run as a courtesy runner for the pitcher or the catcher and then be used as a substitute for another player in that half inning. If an injury, illness or ejection occurs and no other runners are available, the courtesy runner may be used as a substitute.

6. The umpire-in-chief shall record and announce to the scorer, courtesy runner participation.

7. A player who violates the courtesy-runner rule is considered to be an illegal substitute.

EXCEPTION: Should an injury, illness or ejection occur to the courtesy runner, another courtesy runner for the pitcher or catcher may run.

Ozzy . . . .

Nicely done.
No more need be said.

Sounds like this is a point not covered. I would go with: an injured courtesy runner who is replaced with another courtesy runner may return later, as a courtesy runner or as a sub.

Yeah, seems to me like if the CR is injured or whatever, it's just as if he's subbed out for another CR and not treated differently.

Too late!

Thanks Guys!