Ian Prendergast, the AFLPA general manager of player relations, says the match review panel was right to hand Carlton's Bryce Gibbs a three-down-to-two-week suspension for his sling tackle on Port Adelaide's Robbie Gray on Saturday.

This decision has sparked criticism, led by AFL great and Age columnist Wayne Carey, who said if tackling of this kind was disallowed players then "might as well play ring a ring o' rosie".

Gray had his arms pinned and could not protect himself when his head violently hit the ground. He left the field and did not return.

However, Prendergast, while also defending Gibbs' toughness, having alluded to a condescending tweet from former Power captain Dominic Cassisi that  "it's only taken eight years for Gibbs to lay a tackle", has moved to put players on notice.

"Like it or not, tackling players have a duty not to knock an opponent out by slinging or driving them into the ground," Prendergast said.

"The MRP has a difficult role in interpreting these incidents, and no doubt players will feel harshly done by at times depending on the circumstances – as Bryce does on this occasion –  particularly when they are being judged more harshly on the outcome, rather than on its similarity to other incidents.

"But given the concerns about concussion and the incredible courage that players display in the modern game when attacking the contest, the players and the (AFLPA) game group is supportive of the player with the ball being protected.

"Ironically, I have noticed Bryce copping some stick on social media about the style of his play, despite only 31 players in the AFL last year having more tackles. More than 13,500 tackles have been made this year.

"I don't think anyone wants to see a trend emerging where players are being knocked out by opposition players executing what some have described as the 'perfect' tackle. Especially considering players are constantly striving for perfection."

In a message posted on the association's website, Prendergast, a former hard-nut Carlton player, said avoiding dangerous tackles had been discussed through the pre-season.

"The players and the game group discussed dangerous tackles, where a player's arms are pinned and he is slung or driven into the ground, earlier in the year," he said.

"Following a fascinating discussion amongst members of this high-calibre group, they came up with a really mature position on the issue.

"While players were comfortable with where the adjudication was at, they asked that it be monitored by the AFL and were of the view that a player tackling has a duty of care not to slam an opponent's head into the turf through a double-action tackle, with the intent to inflict injury, particularly if it involves lifting an opponent."

Gray's heavy hit came at a time when concussion and the impact of head injuries are a growing issue, and could one day to lead to a mass class action.

Former champion forwards Jason Dunstall and Jonathan Brown have also agreed with Carey that the Gibbs' tackle - a technique taught by clubs - should have been allowed.

"What I can't cop is any suggestion that decisions like this are making the game soft," Prendergast said.

"I spoke with Leigh Mathews at length this week, arguably the best and hardest player of all time, and he said the game has never been more physical. Nor have players, in his view, ever displayed the reckless abandonment and total disregard for their safety that they do in the modern game."