THE AFL will permanently introduce a rule trialled during the pre-season NAB Cup and NAB Challenge games outlawing deliberately rushed behinds.

It was one of two trial rules approved by the AFL Commission on Friday which will come into effect for the Toyota AFL Premiership Season, starting on Thursday, March 26.

The other was to award a 50m penalty against players who tackle, hold or make high contact against opponents after they have disposed of the ball.

AFL football operations manager Adrian Anderson said the number of deliberately rushed behinds had been increasing and players had shown during the pre-season they were able to keep the ball in play to keep the game flowing.

Anderson said the second new rule was needed to combat a growing trend of players dragging opponents to ground to keep them out of the next act of play.

"The Commission's view was that the deliberate rushed behind rule and the 50m penalty for tackling a player after disposal rule had worked well in the pre-season period and would benefit the game," Anderson said in a statement released by the AFL on Friday.

"The quality of football that has been played over the 2007 and 2008 seasons has been outstanding, and the AFL remains committed to ensuring the game remains an exciting and free flowing spectacle.”

The trial rule regarding a no-go zone behind umpires at centre bounces will not be introduced for the season proper but Anderson said the current laws regarding contact with an umpire, where a player can be free-kicked or reported for making contact, would be strictly enforced to protect the safety of umpires.

“The Laws Committee has been monitoring the increasing trend of deliberate rushed behinds in recent seasons and last year, the clear majority of coaches indicated that deliberate rushed behinds would continue to increase and supported the trial of a rule to discourage the tactic,” Anderson said.

“The strong feedback the AFL received was that more and more deliberate rushed behinds would occur if the rule was not changed. The clear majority of coaches, players and fans expressed the view that the new rule would benefit the game.”

Mr Anderson said the NAB Cup trial rule repeatedly demonstrated that defenders could keep the ball in play, and take the ball out of defence, rather than killing the contest and conceding a point. This saw a greater number of contests around the goal square.

Anderson said the league had consulted extensively with clubs over rule changes since the end of last season and during the pre-season trial period.