At least six recommended rule changes will be put before the AFL executive as the bid to rid the game of congestion gathers pace.
The AFL Competition Committee endorsed the proposed changes at a meeting on Wednesday, which will require approval from the executive and, finally, the Commission before they can be introduced.
AFL football operations manager Steve Hocking was tightlipped about what the six recommendations
However, Hocking said trials would first take place in state league games, with the competitions such as the VFL, SANFL and WAFL "queueing up" to be involved.
Hocking preferred to characterise the committee's recommendations as "game adjustments", saying fans should take "a level of calmness" from the League's approach to tackling congestion.
"We're not looking to drop things into the game to upset the rhythm of the game and that's important to actually call that out," Hocking said.
The committee has directed Hocking's team to do more work on the detail underpinning the endorsed changes, while he said the nature of those proposals would be kept under wraps until state league trial games were conducted in public.
The League footy boss did concede, however, that the widely mooted centre-bounce starting positions – whereby six players would be stationed in each of the defensive 50m
Other proposals the committee is understood to have considered include expanding the goalsquare from nine to 18m, reducing the current rotation cap of 90 and introducing starting positions at around-the-ground stoppages.
Earlier on Wednesday, there was a significant public backlash to McLachlan's comments about potential AFL trial games, with concerns raised about how that would affect the integrity of the competition, the draft and the Brownlow and Coleman medals.
Hocking stressed any AFL trial games would have to be approved by the executive and the commission and said the concerns raised were "things we need to work through".
"Anybody that feels that you'd have teams involved whereby it could affect their draft position, those type of things, I don't think anyone would tip into that," he said.
Hocking was far more bullish about conducting state league trials and said clubs in those competitions were equally keen to be involved provided the game result would not impact their finals race.
"(The state leagues) would be our starting point definitely. We've got an opportunity where second-tier competitions are queueing up to actually trial the things that we're looking at," he said.
Hocking said such trials would be vital as the League looked to finetune its proposed changes given the existing trials with Hawthorn, Brisbane and Fremantle had consisted of just 10-minute halves.
"It was clear today from the group that the trials are excellent but it's only an hour's worth of work," he said.
"I've been very clear on the fact that we're not just going to plug those things in if it causes a ripple effect to the game."
Hocking was unsure whether all six proposals would be tested in every trial game, or whether they would be tested progressively "in layers".
The AFL football boss has repeatedly said any rules changes for 2019 will be communicated to clubs by this October.
