In 2008, wiling away a bitterly cold winter's eve in Dublin, the All Black management hosted a few drinks with the assembled media who were covering the Grand Slam tour that year.
As is often the case at these affairs, the topics of conversation were left-field and light-hearted - such as, which of the All Black tour party would be left standing if the squad were asked to cage fight?
The coaches had an answer almost immediately: they reckoned it would come down to Keven Mealamu and Rodney So'oialo. Neither would give up unless they were dead and both had the mental and physical capacity to take and give relentless punishment.
What about now? What would the answer be in 2014? Owen Franks, Kieran Read and Sam Whitelock are pretty tough characters. Liam Messam wouldn't be put away easily.
These boys would be contenders, along with the veteran Mealamu..
But the two men who may go the distance these days are both about to enter the Super Rugby fray this weekend and are both about to embark on what could be the respective, defining 18 months of their careers.
Ma'a Nonu and Jerome Kaino may well be the two toughest men in New Zealand rugby: they may be the two men who would win the proposed, mythical cage fight.
That was Kaino's first tour in 2008 and he wasn't then the physical presence that he became. He was promising, a great athlete who lacked the discipline and consistency to be a great player. Over the next three years, however, he found his inner steel. He got himself properly fit and with that, his confidence and belief grew.
Go find the youtube clip of him tackling Welsh lock Bradley Davies in 2010 in Cardiff. Sensational. Go find the clip of Kaino buckling back Digby Ioane in the 2011 World Cup semi-final. Sensational.
Kaino went from being a little flaky to being a genuine enforcer - a mentally tough, hard, hard man who doesn't tolerate excuses from his peers. What he will bring to the Blues on his return is a sense of responsibility within the group. Who of his team-mates would be comfortable looking him in the eye if they haven't emptied their own tank?
Nonu is a different type of tough. He plays among the carnage of the midfield and yet is hardly ever dinged. He bounces off things, runs through things, knocks things down and never does it appear to blunt him. He is a piece of titanium and in the test arena at least, he gives 80 minutes of smash and bash without a hint of shirking. It takes courage to play how he does, to give so much physically, so much of the time.
The Blues need that from him on Saturday and beyond: they need him to be 80 minutes of unstoppable power.
Kaino and Nonu...the last men standing in the cage..? The Blues hope so.