What should the referee do if a player enters the field without permission after having requested to leave for medical reasons?

When a player leaves the field for medical reasons, they must receive permission to return to the game. If a player enters the field without the referee's permission after requesting to leave, this is a violation of the Laws of the Game.

The correct course of action in this scenario is to caution the player for this infringement. A caution, typically shown with a yellow card, serves as a disciplinary measure emphasizing the importance of adhering to the rules regarding player conduct and safety.

After issuing the caution, the restart is an indirect free kick awarded to the opposing team. This is consistent with the rules that penalize unauthorized player re-entry during active play. It underscores the necessity for players to respect the game’s procedures, especially concerning health and safety protocols.

In summary, the ability to properly enforce these regulations helps maintain the integrity of the match and ensures that all players comply with the established guidelines.