THE AFL says it has discouraged players from leading head-first into contests, but admits umpires need to remain vigilant when adjudicating those incidents.
The League made changes to the head-first rule at the end of last season, seeking to prevent cases where players were purposefully looking for forceful high contact to draw free kicks.
Adelaide forward Tom Lynch found himself in a compromising situation when he dropped his head into the oncoming pressure of Brisbane Lions defender Justin Clarke in Sunday's game at the Gabba.

Luckily Lynch was cleared of any serious damage to his neck, after being stretchered from the field in discomfort and in a neck brace.
AFL football operations manager Mark Evans said the Lynch case further highlights the importance of cracking down on the tactic.
"I thought we had really good cut through with that at the start of the year," Evans said on Monday.
"There is one difficulty for an umpire; and that is if a person ducks or drives forward and the person tackling comes rushing in, then the tendency is still to pay the free kick to the person who gets high contact.
"It's difficult to adjudicate but we're trying to discourage that."
Melbourne legend Garry Lyon even suggested Lynch, and other players who purposefully draw free kicks in that manner, need to be penalised to outlaw the technique completely.
"We've stopped free kicks for this, maybe the next step is to start paying frees against," Lyon said on's Access All Areas.
"Maybe that's where we've got to get to stamp it out."
With health on the agenda, Evans joined Hawthorn coach Alastair Clarkson, AFL Coaches Association interim CEO Mark Brayshaw and AFL medical director Dr Harry Unglik to launch a new campaign focused on addressing men's health issues in the AFL industry and the wider community.
The campaign – which Clarkson is heading – urges people to trade 'a cigarette for a Nicorette' – whereby they can exchange a single cigarette at Chemist Warehouse stores for a pack of 28 Nicorette patches.