It was floated - by Barry Hall of all people - back in 2008 after his ugly punch that floored Brent Staker, and then revisited briefly last year - mostly by journalists - after Ty Vickery hit Dean Cox.

Now, following the incidents involving Hawthorn stars Luke Hodge and Jordan Lewis over the weekend, the debate has resurfaced, this time with former Essendon great Tim Watson leading the discussion.

"My initial reaction when I was asked about it, I said 'no'," Watson said on Talking Footy on Monday night, in reference to the idea of a "sin bin" rule.

"But then I actually started looking at all the other sports around the world and they have a system whereby someone can be ejected out of the game.

"So I'm thinking, well, why don't we?"

The arguments against are plentiful and powerful.

The coaches' first reaction, for instance, is to treat any potential rule change as an over-reaction.

"Maybe we can bring the offside rule in as well, and just complete the change," Fremantle coach Ross Lyon said sarcastically when asked about the idea in the wake of the Vickery-Cox incident last year.

Their fear is that, once introduced, umpires will feel a compulsion to use it.

The game is hard enough to umpire, says North Melbourne legend Wayne Carey, without asking officials to be on-the-run match review panel experts as well.

"It's such a physical game and there is so many grey areas…you can imagine how many times they [umpires] would get it wrong," Carey said.

"In actual fact, we've take that away from them now with [the match review panel]. They don't even [have to] report players anymore."

But if for a second you were to consider the debate in the context that umpires could be trusted to use a red card only in extreme cases, exactly what would be the harm in having one?

Extreme cases are rare in today's game, former Western Bulldogs star Luke Darcy says, and therefore it is simply unnecessary.

"I think our game at the moment is pretty well self-policed. Jordan Lewis and Luke Hodge, I'm told at quarter time actually apologised to their teammates," Darcy said.

"I don't think we need to jump to that conclusion just yet."

It is a popular viewpoint. But those who take the opposing stance can point to two incidents sent straight to the tribunal in five weeks this season already – Hodge's hit on North Melbourne captain Andrew Swallow and Chris Yarran's hit on Essendon's Paul Chapman – and it's the "off the ball" nature of the altercations that is worrying.

The red card is essentially a deterrent, one most believe the AFL does not need as the tribunal system provides adequate punishment.

But when you add in Vickery's hit on Cox in round 18 last year, it totals to three reasonably ugly incidents in 11 home-and-away rounds. Some parents can tell you even one is too many.

There is no suggestion Hodge, or for that matter Lewis, would or could consciously decide on the night to lash out at opposition players in order to make a stand in an important game against North Melbourne, knowing they risk only missing less-important games in coming weeks against GWS and Melbourne.

Every game is important to professional players, so it seems highly unlikely any would think in that way.

But the fact remains that, even putting it to the "if it ever happened in a grand final" test, a player could potentially make that decision - weighing the pros of taking out a key opposition player in order to help win a premiership, against the cons of missing early-season matches the following year.

As it stands now, there is nothing in place for those extreme scenarios - as there are in nearly every other major sport - other than harsher penalties for incidents in grand finals. In essence, AFL relies on the players to be better than that.

"But maybe it's something we should have," Watson continued, adding "in amateur level [AFL], you can be sent off, junior level you can be sent off".

The most divisive point is fairness, with valid arguments on both sides.

Back in 2008 after hitting Staker, Hall said: "there should be a send-off rule for an act such as mine, particularly if the player injured is not coming back on to the field. It is unfair to have the opposition one good player down when you've just whacked him and you are still able to keep running around".

Of the incidents from Saturday night's North-Hawthorn match, Watson said: "if the North blokes don't come back and play, all of a sudden Hawthorn have got this massive advantage and then, three days later, the blokes that actually did it end up getting two or three weeks".

The problems are, of course, what actually constitutes an extreme case? And who makes that decision and when? And what is the penalty?

Watson suggested officials could review footage of incidents, presumably at the next quarter-time break, to assist with decision-making.

But how do you assess the level of impact? Do you wait until it becomes obvious that the victim can no longer participate before the perpetrator is red carded?

Or would umpires have to assess that the act in question could have put the victim out of the game, and therefore the perpetrator deserves to be punished for creating an unacceptable risk of that happening?

But how do you assess the perpetrator's intention? Former Hawthorn great Jason Dunstall mounted a compelling view on Monday night's On The Couch that Hodge's intention was to not strike Swallow in the head, but instead "give him that forceful one at the top of the chest".

"It looks like a couple of cheap shots, I don't think that's their intention. But in their endeavours to be aggressive and intimidate the opposition… they got it wrong," Dunstall said, assessing the Lewis incident also.

What happens when the intent is not obvious, or is at least arguable?

Although it seems unlikely that a victim could "stage" the type of extreme case the red card would reserved for, Carey also raised the issue of staging.

"Imagine if we had someone act," he said.

In the final analysis, it all seems a bit too hard to get right, and would probably never be introduced - even if it seems strange that, for a sport with as much contact as the AFL has, there is not at least a safety net for an overtly violent act that could potentially and significantly influence the outcome of any match.