Aydın Tiryaki and Gemini AI (2026)

The Fine Line in Football Rules: The Impact of Cards During Substitution

Football laws (IFAB) are designed to minimize “gray areas,” yet certain moments—measured in mere seconds—can determine whether a team continues with 10 men or remains at full strength. The most critical of these moments is the substitution process.

In this analysis, we will examine the impact of red cards shown after the substitution board has been raised but before the process is technically complete, focusing on two distinct scenarios.

The Fundamental Rule: When is a Substitution Complete?

The resolution for all scenarios lies within IFAB Law 3:

“The substitution is completed when a substitute enters the field of play.”

This statement clarifies that the status change between the player leaving and the substitute entering is determined not by the “Board,” but by the “Touchline.”

Case 1: The Player Leaving the Field

Scenario: The substitution board is raised. The player currently on the pitch starts walking towards the touchline. Before crossing the line (or while standing exactly on it), they commit an offense (e.g., against the referee or an opponent) resulting in a second yellow card and subsequently a red card.

Analysis:

Since the substitute has not yet stepped onto the field, the substitution process is not complete. The player leaving is technically still considered an “active player” on the field of play.

Outcome:

• The player is sent off (Red Card).
• The team must continue with 10 players.
• The substitute waiting on the sideline cannot enter the game.
• The substitution opportunity is not technically “used” (though the team is now permanently a man down).

Case 2: The Substitute Entering the Field

Scenario: The board is raised, and the substitute is ready at the touchline. However, before stepping onto the field, they commit an offense (e.g., dissent or unsporting behavior) and receive a red card.

Analysis:

As long as the player has not crossed the line into the field of play, their status remains that of a “Substitute.” They are not an active part of the game. Football laws prevent a team from being numerically punished on the field for the actions of a player who has not yet entered it.

Outcome:

• The substitute is sent off and must leave the technical area.
• The team continues with 11 players.
• The manager can keep the original player on the field or bring in another substitute from the bench to replace them.
• The substitution slot is not lost.

Summary Comparison Matrix

We can summarize this critical distinction in football with the following matrix:

Scenario	Who receives the Card?	Status	Does the Team lose a Player?
Before Substitute Enters	Player Leaving	Active Player	YES (10 Men)
Before Substitute Enters	Substitute Entering	Substitute	NO (11 Men)

Conclusion

Football is a game of lines. Just as the ball crossing the line determines a goal, a player crossing the line determines the team’s fate. The substitution board is merely a “declaration of intent”; the legal transaction occurs only when the cleats touch the pitch.

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A Note on Methods and Tools: All observations, ideas, and solution proposals in this study are the author’s own. AI was utilized as an information source for researching and compiling relevant topics strictly based on the author’s inquiries, requests, and directions; additionally, it provided writing assistance during the drafting process. (The research-based compilation and English writing process of this text were supported by AI as a specialized assistant.)