New Zealand great Conrad Smith has called on rugby's authorities to introduce definitive rules on match and training limits to improve player welfare, instead of focusing on new law improvisations such as 20-minute red cards.

Smith, a former glittering centre who won two World Cups with the All Blacks, is now head of player welfare at International Rugby Players – the global representative body for the game's elite stars.

He insists it's time for top nations – as well as clubs – to abide by strict rules on how much full contact training international players do to limit their susceptibility to injury.

As things stand, World Rugby – the game's governing body – has guidelines on how much full contact teams should do in training, but these are not mandatory.

'There has been a lot of debate on 20-minute red cards, but I think that misses the point,' Smith, now 43, told Mail Sport. 

'It's obviously vital to protect the players on the field and minimise foul play. But foul play is a very rare event and accounts for a very small percentage of player injuries.

'The statistics show they get injured by playing and training too much. The one thing that's difficult for rugby is to introduce training load guidelines across the globe.

'The NFL have managed it, but they can control that because they have 32 teams in one competition which allows for much easier regulation.

'We have teams and nations that play across the globe at different parts of the year, but I've got absolute belief we can pull out bottom lines everyone needs to stick to.

'That will help the players who are most at risk.

'Everyone talks about player welfare being the No 1 priority. World Rugby says that. So too does every individual union. 

'But I think we can be clearer in how we take the next step and provide definitive guidelines on that so it's not just words.'

Players who feature at international level face huge physical demands on their body.

England's top stars are now limited to playing 30 games in a season and are given designated rest periods after Test campaigns under English rugby's new professional game partnership.

MailSport revealed earlier this month the number of English players injured during full contact training in the 2022/23 season was the highest ever recorded.

It is in this area Smith believes more work can be done.

The upcoming Autumn Nations Series matches – which kicks-off with England against New Zealand on Saturday – will see the introduction of a 20-minute red card ruling.

The rule states teams will lose a player for the rest of the match in case of 'deliberate and dangerous' foul play.

Technical offences – such as accidental head contact – can now be punished with a player being sent off, but replaced by a team-mate off the bench after 20 minutes.

The Six Nations, who now run the Autumn Series, said no law chances or trials are considered 'without utter confidence player safety and welfare is front and centre.'

Smith, who believes the introduction of mouthguards which can measure the amount of force players are hit with can help improve their management, added:  'I'm a real believer in player load guidelines and being clear on that.' 

Such mouthguards are now mandatory at Test level as part of the head injury assessment process.

Smith continued: 'There won't always be clear scientific data on this because it's a difficult thing we're trying to measure, but we can't wait for the science to take action because it might never arrive. 

'We've got to make changes based on the knowledge we've got and I think we're at that stage now.'