A group of British and Irish Lions legends have called on World Rugby to abolish substitutes except in case of injury in an open letter demanding the sport's governing body makes the game safer.
The signatories, which include Lions legends Sir Ian McGeechan, Willie John McBride, Sir Gareth Edwards, Barry John, and John Taylor, argue that it would be "grossly negligent" to allow the status quo of eight replacements, often dubbed "finishers" or "impact players", to continue while the risk of injury to modern players remains "unacceptably high" and the game remains "unnecessarily dangerous".
The group's argument is that fewer replacements would increase fatigue in the starting XV, producing less intense and less frequent collisions. The average size of player would be reduced, too, as more of a premium would be placed on fitness and aerobic capacity rather than size and strength.
The letter is addressed to World Rugby chairman Bill Beaumont, and cites an interview he did with Telegraph Sport in January 2020 in which he said he was open to replacements only being used for injured players.
"Rugby union was conceived as a 15-a-side game for 30 players. With the current eight substitutes per side, many of whom are tactical 'impact players' or 'finishers', this can and often does stretch to 46," the letter reads.
"More than half a team can be changed and some players are not expected to last 80 minutes so train accordingly, prioritising power over aerobic capacity. This shapes the entire game, leading to more collisions and, in the latter stages, numerous fresh 'giants' crashing into tiring opponents.
"The simple change we advocate is to allow eight subs on the bench if you must but limit the number that can be used to four and then only in the case of injury. This will make the game safer, a view supported by leading players and eminent members of the medical profession."
The group accuses the governing body of "doing nothing" after backing a law-trial for injury-only replacements after Beaumont voiced his concern the use of eight replacements for tactical reasons had turned the game into one increasingly dominated by "big people... and big hits".
The letter also cites the concerns of former England captain, Dylan Hartley, as well as 2017 Lions captain, Sam Warburton, who said he feared that "if something is not done soon, a professional player will die during a game in front of TV cameras".
"Sadly, more than 18 months later World Rugby has done nothing – yet again it stands accused of all words and no action," the letter concludes.
"So, no more empty words, we call upon Sir Bill to act now in the profound hope that Sam Warburton's words do not become prophetic."
The letter's other co-signers are Ross Reyburn, author of Saving Rugby Union – The price of professionalism, Professor John Fairclough, consultant surgeon and former chairman of the Wales Rugby Union medical committee and Dan Hearn, the former England centre who was left quadriplegic after a mis-timed tackle for the Midlands & Home Counties against New Zealand in 1967.
McGeechan stressed that the group were not seeking to disadvantage teams, but were simply pushing for a "change of approach – not personnel".
"It would mean that your best players are on the field for longer," the former Scotland and Lions head coach told Telegraph Sport. "It would not weaken a team – they would still have good players on the bench if there are injuries – and you can still manage a game over 80 minutes as well as 60 minutes with that approach.
"It is about trying to manage a game with players that are far stronger and fitter, to have an outcome that reflects fitness levels and intensity over 80 minutes rather than 60 or 20 minutes.
"South Africa can continue to out-scrum the Lions, but it also means the Lions cannot change their players, either. So, if South Africa get an advantage in scrummaging, lineout and mauling, it stays with them, because their opponents cannot change tack.
"This would help smaller nations, too. If rugby genuinely became a 23-man game, then it does put certain countries on the back foot, just because of depth."
Taylor, who played in all four Tests in the Lions' first and only series win in New Zealand, in 1971, told Telegraph Sport that he thought the move was vital to begin tidying up the sport, which had become "a mess".
"The premise of [the issue] is that there is less space on the field, the game is becoming more gladiatorial, and it is suffering for it," Taylor said.
"As games of rugby, regardless of the fact that the Lions blew it, the second and third Tests against the Springboks were horrible spectacles. If someone were looking at rugby for the first time to see what all the fuss was about, they would not have been in any way turned on to the game.
"We are trying to stir World Rugby into action. They talked a good game for years and have done nothing. They are shockers on that."
A World Rugby spokesperson told Telegraph Sport: "World Rugby is acting in line with the latest science, research and data to make the sport as safe and accessible for all – at all levels, and for men and women.
"Central to this approach is a comprehensive review of the impact of substitutes in the elite game being undertaken across more than 2,000 matches by the University of Bath examining whether more injuries occur later in matches, whether starters or substitutes are more likely to be injured, the positions with the most exposure and the nature of injuries.
"This study is at preliminary review stage and once completed and peer reviewed, the outcomes will inform our ongoing injury-prevention approach."