What is the ruling when an illegal substitute is discovered playing second base?

The ruling regarding an illegal substitute being discovered is that the illegal substitute is ejected upon discovery. This is an essential aspect of maintaining the integrity of the game. When a player who is not eligible to participate enters the game, it undermines the fairness of competition. Ejecting the player not only addresses the immediate infraction but also serves as a deterrent against teams attempting to circumvent the rules.

The other options—warning the player, allowing the game to continue without penalties, or granting a timeout to address the issue—do not effectively handle the infraction of having an illegal substitute. These alternatives may lead to confusion over player eligibility and could encourage disregard for established rules, which is contrary to the principles of sportsmanship and fair play. Thus, the ejection rule is firmly in place to uphold the standards set by governing bodies in sports competitions.