What happens if a player showing concussion symptoms is later allowed to return to the field?

If a player who shows symptoms of a concussion is allowed to return to the field, it counts as a reentry. This is because, in the context of concussion protocols, once a player shows signs of a concussion, they are typically evaluated to ensure their safety. If they are cleared to return after appropriate assessment, they can enter the game again. However, this reintegration into the game must be in accordance with the sport's specific rules regarding substitutions and reentries.

It's important to recognize that safety protocols around concussions are stringent to protect the player’s health, and proper evaluation must occur before allowing any return. The other options don't align with the standard procedures established for player health and game management. Permanently removing a player serves a different protocol, while the return of a substitute instead of the original player does not apply when a player is cleared to play after a concussion assessment.