Elite rugby union could see the introduction of orange cards after World Rugby on Thursday unveiled trials of 10 temporary optional laws to cut the risk of coronavirus infection.
The measures, designed mainly for recreational rugby, include a drastic reduction in the number of scrums per match, limiting numbers in a maul and quickening up rucks.
In rugby union, a yellow card leads to 10 minutes in the sin-bin with a red card seeing a player sent off.
The suggested orange card, which would apply only to the professional game, is designed to reinforce high-tackle guidelines and reduce face-to-face contact.
It would apply to potential red-card offences, with a player removed from the field while an incident is checked by the television match official.
If deemed a red-card offence, the player would not return. If not, they would return after 15 minutes.
One persistently thorny problem for professional rugby union, long before Covid-19, has been the amount of time it takes to reset a scrum.
But the proposals include doing away with scrum resets, to be replaced by free kicks or penalties. Where "no infringement occurs" the ball goes to the team with the scrum put-in.
World Rugby estimated the changes could reduce scrum contact exposure by more than 30 percent.
"We have extensively evaluated the perceived risk areas within the game," said World Rugby chairman Bill Beaumont.
Measures would, however, be implemented at the discretion of individual unions based on the risk of virus infection in their countries and government guidelines.
And the Welsh Rugby Union soon signalled their opposition by saying they had no plans to implement any of the law changes.
"I'm not a fan. I think it eats away at the integrity of the game," WRU chairman Gareth Davies told the BBC.
"There are a couple of positives there, looking at the scrum, it would be great if we could put something in place long-term."
"(But) At the moment, our Union has no firm plans to implement them."
Davies, himself a former Wales fly-half, added: "Is it equitable that the risk to the fly-half, for example, is a tenth of the risk to the prop forward or the second row?
"If there is any risk, changing the laws or not, we shouldn't be playing."
Meanwhile England's Rugby Football Union said it "recognised" World Rugby's work but added it had its own review under way looking at options for returning to training and playing.
Hygiene protocols put forward by the global governing body include the use of hand and face sanitiser and washing the ball.
Players would, where possible, be asked to change their kit at half-time and have been advised to avoid pre-match huddles, hugging team-mates in celebration, and spitting.
When training, scrum practice should be against a machine rather than another set of forwards, with high-risk transmission exercises such as scrummaging and mauling avoided within 48 hours of a match.
Many in the game fear rugby could lag behind other sports in making a return because it is a full-contact sport, but Australian rugby league restarted on Thursday with a match between the Brisbane Broncos and Parramatta Eels.
With this year's Six Nations still to be completed and the whole July programme of international matches in the southern hemisphere postponed due to the pandemic, rugby union faces the prospect of huge financial losses worldwide.
World Rugby, however, has put in place an £80 million ($98 million) funding package for the global game and there are hopes the postponed Tests can be played later this year.