Mmh, not sure you can caution a substitute for "entering the FOP without permission"
http://www.fifa.com/mm/document/foo...7_06_2014_new--lawsofthegameweben_neutral.pdf
p38/39
A
player is cautioned and shown the yellow card if he commits any of the
following seven offences:
• unsporting behaviour
• dissent by word or action
• persistent infringement of the Laws of the Game
• delaying the restart of play
• failure to respect the required distance when play is restarted with a corner
kick, free kick or throw-in
• entering or re-entering the fi eld of play without the referee’s permission
• deliberately leaving the fi eld of play without the referee’s permission
A
substitute or substituted player is cautioned if he commits any of the
following three offences:
• unsporting behaviour
• dissent by word or action
• delaying the restart of play
If the law says that a substitute is cautioned for the three offences above, it's pretty clear to me that he can't be for the other four