Hawthorn coach Alastair Clarkson has urged the AFL to discourage players from deliberately drawing free kicks for high contact.
Clarkson said the umpires should call "play on" as he used Geelong captain Joel Selwood to emphasise his concern over head knocks.
"If we're actually fair dinkum about head injuries and trying to (prevent them), we shouldn't be providing extra protection for someone who contributes to the high contact," he said.
"All that's doing is encouraging more and more players to use that tactic.
"Joel has had them (head injuries) himself. If he's going to keep playing like a bull in that sort of manner and whilst he's going to continue to get those sorts of free kicks. But he has had 10 concussions in his career or thereabouts.
"The concern isn't for him right now, the concern is for him and the game in 10, 15, 20 years’ time.
"If we want to do something about concussion, we should be policing the game in a manner where dropping the knees, shrugging the shoulders, raising the arm, ducking the head, all those sorts of things - we could get that out of the game really quickly if we were fair dinkum about it.
"As we've seen in the States, concussion is a significant issue and at the moment we're thinking we're protecting the player by paying a high free kick every time he drops his knees or shrugs his shoulder when in actual fact we're not doing the game any good by doing that for the player."
On whether a free kick should be played against the ducking player, Clarkson said: "It should be just play on. It would be too harsh to go the other way to have a penalty for it.
"I just think concussion is going to be a significant issue unless we do something about this rule.
"We've spoken about Joel which is a little unfair because a lot of players do it. And Poppy (Hawthorn forward Paul Puopolo) is probably a ripper for us.
"Poppy is probably a little different because he's shorter again, but it's still a natural movement of his to throw the shoulder and get low and he gets a lot of free kicks.
"This isn't a Joel Selwood rule, this is a game rule. It's about what's best for the game.
"It would impact on Paul Puopolo and James Sicily as much as Joel Selwood if it was to be changed, but I think that's best for the game."