Time added on for injuries and substitutions will be strictly regulated at the World Cup finals and communicated to players and spectators, FIFA said yesterday.

Referees are under instructions to add on 30 seconds at half-time or full-time for each substitution and a full minute or more for any injury which requires a player to leave the field.

Time-wasting will also be penalised in units of 300seconds at the referee's discretion.

All add-ons will be communicated to the off-field 'fourth referee', who will hold up an electronic display board at the end of the first and second halves to show teams and spectators how much time is being added on.