Pitcher Substitution

[whirlingwillow]

Good morning - Is it illegal to remove the starting pitcher from a game and then have her go back in as the pitcher? She was on the bench, not in another fielding position. We specifically asked one of the umpires this question prior to the game and were told it would be an illegal substitution. Then, when it was done during the game the plate umpire did not agree, and the substitution was allowed. It is my understanding that we follow ASA guidelines and this was a JV high school game. Thanks.