What action can lead to a player receiving a straight red card?

A player can receive a straight red card for serious foul play or for denying an obvious goal-scoring opportunity because both actions are deemed severe violations of the Laws of the Game. Serious foul play typically involves any tackle or challenge that is considered reckless or endangers the safety of an opponent. This could include violent conduct, such as a high kick or a tackle from behind that makes contact with the opponent's body in a dangerous manner.

Denying an obvious goal-scoring opportunity occurs when a player infringes the Laws of the Game, such as committing a foul that prevents an opponent from having a clear chance to score. The criteria for this typically include the position of the players and the likelihood of scoring if the foul had not occurred.

In both scenarios, the intention is to maintain the safety of players and the integrity of the game by penalizing those who act in a reckless or dangerous manner. These actions are serious enough that they warrant immediate dismissal from the match, hence the straight red card. In contrast, other actions mentioned, such as receiving two yellow cards, requesting a substitution, or excessive celebration, do not meet the same threshold of misconduct that would necessitate a straight red card.