Official Game Line Up Card

Question
I am an American Legion coach and we are currently playing in our state tournament. We play American League rules in American Legion.  Question:  The other team inserted a player in the line up that was not listed as a sub on the official game line up card that was exchanged at home plate before the game started.  Is this player illegible to play in the game?

Answer
Stephen,

Depending on how strict the rules were, the player could be ineligible to play. In Major Leagues, the managers must have all eligible substitutes listed on the roster given to the Home Plate umpire. However, in high school, it's only a courtesy and is not required.