SEEKING to demystify why yellow card are given, I am looking at the third of the six offences which is ‘entering, re-entering or deliberately leaving the field of play’.

Entering covers anyone turning up late for a game, when the referee decides at what stage of play they can come onto the pitch.

It also covers substitutes who can only come on at a break in play, after the player coming off has left and at the halfway line, once they have received the referee’s signal.

Re-entering the field of play is aimed at players who go off the pitch, for or after injury treatment or to correct some equipment.

In these instances, it is not required that the player comes on at the halfway line, but it must be from the touchline if the ball is in play.

If play is stopped, the player can return from the goal line, but must still wait for the referee’s signal.

I remember an incident at Madejski Stadium when a player who had been injured and was waiting on the touchline, ran on the pitch to intercept a pass down the wing.

The Law today requires the referee to also award a direct free-kick, but an indirect free-kick if the player didn’t interfere with play.

Deliberately leaving the pitch is rarer, although I read recently of a player who had been cautioned, showed his displeasure by deliberately walking off the pitch.

The referee quickly showed him a second yellow card, followed by a red one.

A little-known instance occurs when a defender deliberately walks off the pitch to put an attacker in an offside position.

It wouldn’t work as he would be considered to be on the goal line and he would receive a yellow card for leaving the pitch without the referee’s permission.

Also, if an attacking player steps off the pitch to show he is not interfering with play but returns and interferes before play is stopped, he will be cautioned for re-entering the pitch without the referee’s permission.