In case an injured player's condition deteriorates, ensure that he/she is supervised at all times.
Major chest or abdominal injuries in Rugby are extremely rare. However, if they do occur, they often can remain hidden and only present late due to blood loss or “shock”.
Ensure all players who are removed from play with injuries have adequate supervision and are not left alone, just in case their condition worsens. Have a low index of suspicion for asking for help or hospital for anyone you are not happy about.