Players boss Damien Hopley has called for urgent action to be taken after 23 of England's 40-man elite squad missed training on Monday because of injury. "We need to look at training methods and rest times, and the psychological, emotional and physical strains placed on the players," Hopley told BBC Sport.
"It is a growing concern and something has to give. Unfortunately it always tends to be the players' bodies.
"At any one stage in the season, 25% of the players will be injured." Hopley, the chief executive of the Professional Rugby Players' Association, admitted it was "ironic" that so many of England's players were injured when "this has probably been the best off-season a lot of them have had".
Charlie Hodgson, Jonny Wilkinson and Josh Lewsey were excused from England's summer tour of Australia so they could rest, and Lawrence Dallaglio and Jonny Wilkinson were absent because of injury. Hopley believes the main problem is the way the game is structured in England, rather than the sheer volume of matches played.
"I think playing too much rugby is probably a bit of a red herring," he said.
"I think we need to take a holistic approach as an industry and we are doing a lot of research into this.
"We conducted a survey of the players last season and I think 80% of the players felt that injuries were increasing in terms of severity.
"So we know it's a big issue and it's really up to us and employers - both the rugby union and the clubs - to look at how we can address this and come up with a better structure which reduces the risk to the players."
World Cup favourites New Zealand and two-time winners Australia are among the countries who centrally contract their top players, which means national coaches have complete control over them. That is not the model in England, where clubs have much more power, and Hopley believes it is too late for central contracts to be introduced into the English game.
"Clearly there are some within the Rugby Football Union who rue the day they didn't centrally contract players, but we are where we are," said Hopley.
"I think the issue of injury and, dare I say it, burnout, is a growing concern for the entire global game because of the sheer collision nature of the sport now.
"I think a lot of England players at the elite end would like to be managed jointly - ie by the club and the RFU.
"But I can't see central contracts being introduced with the current, shall we say, fractious relationship that exits between the clubs and the RFU."
Story from BBC SPORT: