There's long been a phrase in English football where managers ask of foreign players whether they can do their magic on a wet Tuesday night in Barnsley.
The implication was that the latest hotshot signed from wherever could be a wizard on his home patch on a sunny Saturday afternoon, but not so keen to guts it out on a mud heap in front of 30 people.
It was horribly xenophobic, but the grouchy old men steeped in the rough and tumble of British football had a natural lack of trust in foreign players, believing that most lacked heart or the same sort of fabric as the lads from the local estate.
In the Super Rugby allegory, the Blues are the foreign players. They managed to put it all together in their opening game against the Rebels and they looked a little bit special.
But the Rebels look destined to finish in the bottom four and were a shambles for the better part of 60 minutes.
The Chiefs, in Hamilton, present as a wet Tuesday night in Barnsley and a more accurate gauge of what the Blues are really all about.
The intensity of this week's contest will be significantly higher than last week's. The Chiefs will bring better defensive linespeed. The contest for the ball will be ferocious both at set piece and at the tackle.
It will be proper rugby and as a result, plenty of questions will be asked of the Blues' physicality, resilience, creativity and maybe most importantly, their character and decision-making.
That they have ball carriers and linebreakers is plain for all to see. That they have a muckle-big tight five is just as obvious. They can scrummage and hold their own where they need to. But niggling away in the background is this uncertainty about their composure and option-taking.
Do they have the patience to break down the Chiefs? It won't happen quickly or easily, so can Ihaia West and Piers Francis find the space and work out how to exploit it? Will West be ready to kick as much as he did in Melbourne and execute it with the same accuracy?
The Chiefs didn't overly impress in their first outing but what they showed was that invaluable quality of finding a way to win a scrappy contest. They won the key moments against the Highlanders and rode their luck.
Not flash but effective and at this stage of the season, coaches are often happy enough to see passion and fight, knowing that they are the harder assets to instil and that the polish will come in time.
Under coach Dave Rennie, the Chiefs have shown they can go to Barnsley and win. In fact, that's been their defining gift in recent seasons - their tenacity to stay in the fight and give themselves a chance. And more often than not, if they are in the hunt come the death, they win.
So Friday is a big game in the context of the Blues' season. It should reveal plenty about their readiness to attack Super Rugby's summit.