AFL football operations manager Adrian Anderson told the Herald Sun newspaper that four umpires will be rotated through the games, with each umpire on the ground for three quarters each.
The rule change, which Anderson said was mooted by West Coast Eagles coach John Worsfold, will be looked at further by the Laws of the Game committee following a varied reaction from the rest of the competition.
“The response we got from the clubs was mixed”, said Anderson.
"Certainly it wasn't something unanimously supported. There was a wide range of views on [four field umpires] so it was something we were considering, but we never said there would definitely be four in the NAB Cup.
"It may be something we consider further, but not this year."
But other coach-led innovations will be trialed during the pre-season competition, including the rule to pay a free kick for deliberately rushed behinds.
"The free kick for a rushed behind was one that Neil Craig put forward and a majority of clubs and coaches agreed we should do something about deliberate rushed behinds,” Anderson said.
"We thought it would increase if we didn't do something about it.
"It's a clear deterrent and consistent with the rule book, where you can't take the ball deliberately out of bounds anywhere around the ground and it doesn't involve changing the scoring system, so we'll be interested in looking at that as well."
A player who is taken to the ground after disposing of the ball will receive a free kick in another rule to be trialed in NAB Cup matches.
A third trial rule was proposed by St Kilda coach Ross Lyon and will see the introduction of a player-free zone behind umpires as a means of minimising player-umpire contact.
