What happens if an illegal player is discovered after a batter has hit a double?

When an illegal player is discovered after a batter has hit a double, the ruling states that the illegal player is out and the play stands, but the runners remain on their bases. This means that the action on the field prior to the discovery of the illegal player is upheld, and the runs or advancement that occurred during that play are not affected. The out rule applies to the illegal player, ensuring that the integrity of the game is maintained, while also recognizing that the play that took place was valid.

In this scenario, the focus is on maintaining the outcome of the play that just happened, ensuring that the advancement of the legitimate players is not undermined due to the presence of the illegal player. This reinforces the importance of compliance with player eligibility while allowing for the flow of the game to continue without disruption from errors in player identification.