Rugby Football Union's former director of professional rugby Rob Andrew believes the selection of rugby league convert Sam Burgess was the tipping point of England's 2015 World Cup debacle under Stuart Lancaster.
Burgess was fast-tracked into the England World Cup squad just after he switched codes to play for Bath during the 2014/15 season but the 28-year-old found it tough to adapt to the rugby union and his failure led him to return back to rugby league following the World Cup which saw the red rose team make a first-round exit.
The performance of England in the World Cup that saw them lose to Wales and Australia costed Lancaster his place and was eventually replaced by Eddie Jones.
In a section from his book, The Game of My Life: Battling for England in the Professional Era, published in the Telegraph, Andrew wrote: "If t here was a problem team-wise in the run-up to the 2015 World Cup, a selectorial Achilles' heel, it was to be found in midfield.
"Try as he might, Stuart Lancaster could not settle on an optimum configuration. Which is where Sam Burgess came in, and where things went horribly wrong.
"I would not even begin to pin the blame for our embarrassing World Cup misfire on a single player, but the kerfuffle around the introduction of Burgess was undeniably the tipping point.
"To this day, I simply do not understand the thinking behind the fast-tracking of a player from international rugby league to international rugby union when so many of the things that had made him wildly successful in the 13-man game were of questionable relevance in the 15-man version.
"It was an almighty risk to select him in a World Cup squad on such extremely limited and highly questionable evidence and it proved to be an almighty blunder.
"Why did Stuart do it? He alone knows the truth of the matter. But all head coaches are control freaks in their own ways, especially around the matches and tournaments they know will define them, and Stuart became pretty dictatorial in the way he ran the show in 2015."