World Rugby will consider introducing the 20-minute red card as a global law trial despite concerns that it could diminish the deterrent effect.
The law, which is being trialled in Super Rugby, means the dismissed player can be tactically replaced by a substitute after 20 minutes.
England lock Charlie Ewels was sent off after 82 seconds against Ireland in the Guinness Six Nations last month, with many observers feeling the dismissal ruined the game as a contest.
World Rugby, however, is determined to keep lowering tackle heights and the Super Rugby trial so far has proved inconclusive.
“That’s been discussed before and will be discussed again,” World Rugby chief executive Alan Gilpin told the Daily Telegraph.
“It would be great if more competitions, even in a closed trial, would use it because that would give us more of an overview of the effect it would have on the game.
“We need to see more of the data to see whether that strikes the balance between safety and spectacle better.
“There is more work to do to analyse that and the concern is, if a team goes back to 15 players, is that enough of a deterrent to drive that behavioural change.
“We would like to see it trialled more widely before drawing any conclusions.”
