Rugby union referee Nigel Owens says the sport must "do everything" it can to limit serious injuries.
Wales winger George North will not play again this month on the advice of a neurologist after suffering four head injuries in the last five months.
Owens suggests tackling technique and head protection are areas to explore.
"It is a contact game and unfortunately some serious injuries happen," said Owens, who has been an international referee since 2005.
"We need to do everything we can to make them happen less often."
Owens was speaking on Radio 5 Live's Friday Sports Panel, and then later spoke to the BBC to clarify his comments.
He said: "You could make it compulsory that every player has to wear a head-guard.
"I do not think that would stop every concussion but it would give you safety regarding it.
"The other thing is getting the tackling technique correct, putting the head in the right place, make it as safe as you possibly can.
"But would they work? I don't know. I'm not sure what we can change in the laws of game that would make it safer, apart from taking the head collision away somehow."
North was knocked out as Saints beat Wasps 52-30 in a Premiership Game on 27 March.
The wing missed Wales' 12-6 win over South Africa in the autumn internationals after being concussed against New Zealand, and was then struck twice on the head while playing against England during the Six Nations.
Former World Rugby medical adviser Dr Barry O'Driscoll has said that North should not play again this season.
Owens added: "The medical experts will give their opinions and at the end of day it will be down to George to decide."