England are constantly reminding themselves about the threat their first World Cup opponent, Fiji, represent in a match which kicks off the tournament on Saturday NZT.
For the All Blacks, their first opponents, Argentina, don't need to be talked up. They would have been aware of the threat as soon as the draw was made because Argentina have form at World Cups.
The Pumas, who pushed the All Blacks hard in their quarter-final at Eden Park in 2011 before the home side got on top in the final quarter, finished third in the 2007 edition of the tournament.
They also achieved the remarkable feat of beating the Springboks in Durban in this year's Rugby Championship.
They are big, powerful men not fazed by playing on the big stage and that is why they are the perfect first game for the All Blacks. There will be an edge about Steve Hansen's men this week as they prepare for the match at Wembley on Monday NZT because it will be the defining one of their pool as far as they're concerned.
"When you look at the likes of Namibia and Georgia and Tonga, they're going to be very physical teams so we've got no doubt we'll be in some battles in that regard," assistant coach Ian Foster said.
"Clearly Argentina are considered one of the favourites to go through in this pool so it's great to get them first up. It's going to be a big game for us.
"We've built up a lot of respect for them having played them a lot over the last few years.
It's never been easy. So if you look at where they have come from - they beat South Africa this year - they're a team becoming more comfortable with what they do. It's certainly a massive challenge for us in week one and it's the best way for us to start, I think."
The potentially good news for the All Blacks is that they will know what they will get with Argentina; a set piece-focused opposition with a big emphasis on kicking, no matter their recent experimentation of playing a wider, more expansive, game. Their defence can also be notoriously hard-nosed, another reason why they tend to perform well in World Cups.
Jerome Kaino tells a good story about playing the Pumas at the 2011 tournament. It was the big loose forward's first match against them, and the ball kept finding him from kick offs. It was his job therefore to keep running it back at a blue-and-white striped wall in the knowledge that the slightest hesitation would give them a huge psychological boost.
He felt the effects for days afterwards.
The two teams have played each other seven times since the last World Cup, so the All Blacks will have plenty of intelligence on them. Their last match, a 39-18 Rugby Championship victory for Steve Hansen's men in Christchurch, featured two tries for the visitors from rolling mauls.
Captain and hooker Agustin Creevy was the beneficiary both times. After Hansen's appraisal that the lineout drive was a "boring" part of the game, expect the Pumas to go back to the tried and tested. It's something the All Blacks are likely to be ready for.
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