A former Wales coach fears the upcoming Rugby World Cup could be ravaged by a "quick" crackdown on shoulder charges and high tackles.
The rugby world was divided last weekend when All Blacks lock Scott Barrett was sent off in their 47-26 defeat to Australia in Perth.
He received a three-week ban for his red card in the 40th minute when his shoulder and elbow connected with a neck and head of Wallabies skipper Michael Hooper.
England coach Eddie Jones said it was "ridiculous" referee Jerome Garces sent Barrett off while others were backing the top French official for his actions.
And ex-Wales and Ospreys coach Scott Johnson, who will help plot the downfall of Warren Gatlands' Six Nations champions in Japan as Australia's new director of rugby, has concerns over where rugby is heading with the start of the World Cup just five weeks away.
The man who helped mastermind Wales' 2005 Grand Slam alongside Mike Ruddock told Fox Sports Australia Rugby podcast: "There's general concern because there's a major change, a seismic shift really in the way the game's played.
"And certainly the height at which the game's expected to be played at. It is difficult for very big men to get that low but I understand the reasoning.
"It's about safety, I have a personal view of it, I think we've probably moved a little quick for the tournament (World Cup).
"I watched the under-20s World Championship in Argentina this year (where cards flowed freely) and the implication of a red card is quite dramatic in a game."
In May, World Rugby issued new guidelines on high tackles and shoulder charges to provide greater clarity around its attempt to improve player safety.
Johnson added that the rules are clear but he fears for the rugby "product".
"We understand the rules in which we're playing," Johnson added.
"We can only determine our own fate and we have to make sure we play within those laws.
"It's for us as administrators to argue appropriately, in different forums, for what we think is the best interests of the game, moving forward.
"Because at the end of the day we are in show business and we want to make sure that what we put out on show is a product worth watching.
"That's what's important to us."
In May World Rugby outlined its new guidelines in the instances of shoulder charges and high tackles.
The primary aim was to reduce head injuries.
A World Rugby statement said: "The 'decision-making framework for high tackles' was developed in partnership with union and competition delegates and includes players, coaches, match officials and medical input.
"It is a simple step-by-step guide with the purpose of:
"Improving the consistency in application of on-field sanctions by distinguishing between dangerous tackles that warrant a penalty, yellow card or red card
"Supporting protection of the head of both players by consistently and frequently sanctioning the tackle behaviour that is known to be the highest risk."
