AFL clubs will not be required to nominate their substitute player until 90 minutes before the start of each match under guidelines released by the league on Monday.
The AFL has written to all clubs to outline how the newly introduced substitute system will operate in 2011.
Three players on the bench will be interchangeable throughout the match while the substitute will be able to be brought into the game at any time and for any reason.
The substituted player takes no further part in the match.
AFL football operations manager Adrian Anderson said clubs would be required to nominate their substitute player when final team sheets are lodged on the day of the match to allow maximum flexibility in their match preparation.
A substitute player will be required to wear a green vest until he is activated to play.
The substituted player who is removed from the game will be required to wear a red vest.
The vests will be used to clearly indicate to the opposition and spectators the players involved in the substitution.
Anderson said that clubs may make a substitution at any time that best suited their club on match-day.
"Substitutions will be able to occur at any point of a match and for any reason, including the quarter time, half time and three quarter-time breaks," Anderson said.
"The mechanics of this has been evolving throughout our consultation with the clubs throughout the last year."
The emergency umpire on the interchange bench will notify the on-field umpires of the substitution via the umpires' communication device and this will also be communicated to the match day broadcasters and the scoreboard operator.
If a club sends a substitute player on field before notifying the interchange steward the opposition club will receive a free kick and 50-metre penalty.
The AFL Commission approved the introduction of the substitute rule in October last year based around three reasons for restricting the interchange - congestion, fairness and injuries.
The laws committee was concerned that, if left unchecked, further increases in the use of interchange would make the game more defensive and more congested.
"The whole idea of introducing a sub was to prevent rises in interchange taking game speed to a new and dangerous level and the congestion that would result from that," said Anderson.
"It will have the effect of limiting the interchange."
Two substitutes will be used during the NAB Cup.