Daniel Carter limping off training grounds has become a worryingly familiar sight. It never used to happen. Carter, for most of his earlier career, appeared to train and play in bubble wrap.
There would be the occasional serious injury - a broken leg in 2005, the damaged Achilles in 2009 and of course the groin rip in 2011. But he wasn't an athlete riddled by niggles, fiddly tight muscles that would pick inopportune moments to tweak and stiffen.
This year has been different. He tweaked his hamstring during the second test against Ireland and he missed the third. A few weeks later, he strained his calf and missed the tests against Argentina and South Africa and now he's in danger of missing a fourth international due to a leg problem he picked up at training on Thursday.
No one should unduly fret or see these regular injuries as a sign that Carter is beginning the slow descent. Only two weeks ago, he was running like a man five years younger, splitting the Scottish defence and looking incredibly like the greatest first-five to walk the planet.
His world hasn't collapsed in just two weeks: he's only 30 for goodness sake, the age at which Frank Bunce made his All Black debut and there were mitigating circumstances.
The University of South Glamorgan training venue was a peat bog: all that squelchy, heavy mud and all those highly-toned muscles - bad mix.
But why did it have to be Carter's leg that gave way? And that's just the thing, he is what the All Blacks call a red flag athlete. He remains imminently capable of playing breathtaking rugby and doing it all the way through to 2015. But he is also becoming more susceptible to soft tissue injuries. That's partly his age and partly a consequence of the punishment his body has taken in a decade of professional rugby.
His future now might involve more episodes like these where he feels a twang or a tweak. That is the sad, inescapable truth. The big donkeys in the tight five can probably run blissfully unaware into their mid-30s that they even have hamstrings and the like, but not the finely crafted, sculpted works of art like Carter.
A heavy pitch, a cold day and New Zealand's most precious asset will be susceptible. Maybe it's too much rugby. Maybe Carter needs to be more carefully managed than he already is.
If nature, or the rugby gods, or whoever it was that kept him safe up until last year can't do it anymore, then maybe it's time for more active strategies to kick in. How much Super Rugby does he really need to play? The Crusaders have three first-fives in their squad, maybe it's time to keep Carter for the biggest games and only a handful of others? If the All Blacks see another heavy training field to the one they encountered in Cardiff, maybe they need to tell Carter to stay on the bus.
Perhaps buoyed by the injury to Carter, Wales will tomorrow morning go searching for their first win against the All Blacks since 1953.