James Haskell believes England's tour of Argentina this summer in "hostile" conditions could prove crucial to their bid for glory at the 2019 World Cup.
England's two-Test series with the Pumas next month gained extra significance following Wednesday's 2019 World Cup pool draw that paired Eddie Jones's side with Argentina and France.
England must endure the toughest pool for the second competition running, but Wasps flanker Haskell remains unfazed by the challenge - instead relishing this summer's battles in Argentina.
Haskell believes facing partisan crowds and coach Daniel Hourcade's full-strength side in June will prove invaluable when it comes to the culture shock which awaits at the tournament in Japan.
"Argentina play all year, are in the Rugby Championship and are super dangerous," said Haskell. "That is why it is interesting on this tour in the summer, playing their full-strength side.
"If they had played in the right areas against Australia in 2015 they could have beaten them and reached the final. They will have that experience and they are a tricky team to play.
"In picking youth Eddie [Jones] has gone another tier down and given guys the experience of going to a hostile place this summer. We're not going to particularly well-known places in Argentina. Everyone on the tour will be playing for their future in an England shirt.
"All that will be an example of what is going to happen in Japan and the ability of a team to adjust."
Haskell had a stint at Japan's Ricoh Black Rams between 2011 and 2012, and admitted the country can prove tough going for a westerner.
"Culturally it's very different; the language barrier is one thing because when so many languages are based on Latin you can just about get a few English words - but with Japanese there's nothing," said Haskell. "So if you get lost in Japan, you're fully lost, if you can't read Japanese you're in hell.
"You'll be spread out quite far, the ability to explore and go around is an interesting one and you'll spend a lot of time together as a squad. The England boys are in camp at the moment and are apparently getting absolutely destroyed because Eddie wants to ensure the standards are met.
"Argentina is not a Saxons tour. It's a full-on England tour. If you don't deliver in that environment - and this goes for me, Dylan Hartley, Danny Care and the young kids too - you will be out of the door."
Rory Teague will leave the England set-up to join Bordeaux after the Argentina tour, leaving Haskell to praise the skills coach's work under taskmaster boss Jones. Haskell tipped Teague to fast-track his career by meeting the challenge of coaching overseas.
"I am a huge believer in taking yourself out of your comfort zone," said Haskell. "If I was a coach I would love to go to Super Rugby, see what they do over there from a coaching perspective; I'd love to go to France.
"I'd say work with Premiership teams, sevens teams - get that whole experience then formulate your own ideas. To be a successful coach you have to know what you are about.
"You can't be all things to all men - you have got to know what your limitations are but be open-minded to improve. Those are the best coaches. Eddie says 'this is my way, this is how I am going to do it and I am here for four years; If it works it works, if not I have kept my integrity'.
"Rory going to Bordeaux will be a massive eye-opener, it will be very intense, but fantastic."