THE AFL Umpires' Association says it would be open to a new NAB Cup rule protecting its officials being introduced in the home-and-away season.

In the AFL's pre-season competition, a two-metre "no-go zone" will be enforced behind an umpire backing away from a centre bounce, and a free kick will be paid against any player entering that area.

Collisions between players and umpires increased five-fold last season, with 17 reportable incidents involving players making contact with officials. All these involved centre or field bounces.

It was reported in Melbourne's Herald Sun newspaper on Wednesday that AFL Umpires' Association chief executive Bill Deller believed the new rule could prevent an official from serious injury.

"We are delighted that they have taken into account some issues that concern us and the umpires. It will be interesting to see how this rule works," Deller was quoted as saying in the article.

"When the contact is from behind, the umpires aren't expecting it and some of these contacts have been quite heavy. There certainly is the potential for an umpire to be hurt."

Deller said, pending the results of the trial, his organisation would be open to the rule's introduction in the season proper.

Players will be allowed to pass in front of an umpire once he backs away, but are prevented from entering the 'zone' behind the official, which extends 6.5m back from the centre bounce.

A memo from AFL football operations manager Adrian Anderson to the 16 clubs last week gave an explanation of the trial and the reasons behind it.

"The only path away from the stoppage is directly backward and when players are in this position the umpire is impeded from moving safely away from the stoppage to adjudicate the contest," the memo stated.

"The new rule is designed to prevent players from starting in dangerous positions, discourage the use of umpires as a screen to break tags, and raise awareness of the importance of players not starting or moving to a negligent position behind the umpires."

The Herald Sun article also quoted Deller as saying the umpires were becoming more comfortable in their adjudication of the hands-in-the-back rule.

The Laws of the Game Committee strongly considered whether to allow incidental contact into the rule, but felt it would have been impossible for umpires to adjudicate.

"It has to be in [the back] or out," Deller said.

"The rule had its teething problems. But it seemed to us it had settled down towards the latter part of the season."