Just wanted to pass this on. Taken from the 2005-2006 ASA Casebook:

PLAY 8.11-7
In the top of the 1st inning, the listed pitcher leads off with a single. The manager reports a CR1. B2 gets a base hit and CR1 slides safely into 3B and is injured. The team has no other legal substitutes. The managaer requests that the pitcher returns and runs.

RULING: Legal. Should an injury occur and no other substitutes are available, the pitcher must return and run for himself. (8-10F EXCEPTION)

Serg