The Crusaders will name their team to play the Chiefs on Thursday and the first name New Zealand rugby supporters should be looking for is Sam Whitelock's.
The new All Blacks captain hasn't played for two weeks due to concussion; he missed the Crusaders' win over the Blues at Eden Park and their recent victory over the Hurricanes at AMI Stadium which reinforced their place at the top of the Super Rugby table.
If he misses another crunch derby against the Chiefs at Waikato Stadium – and he didn't take a full part in All Blacks training in Christchurch today - then the clock really is ticking on whether he will be available for the first test against France at Eden Park on June 9.
Steve Hansen will be concerned should Whitelock be ruled out of the Hamilton match but the All Blacks coach will know there is nothing he or anyone else can do about the 29-year-old's symptoms, which were first reported after the Crusaders' victory over the Waratahs in Christchurch on May 12, a match in which Whitelock played 80 minutes.
Hansen will know, too, that with 96 tests behind him Whitelock has the mental and physical fortitude to play against the French regardless of when his last game was.
But the All Blacks' leadership situation, given the absence of regular skipper Kieran Read due to his continued recovery from back surgery (he expects to be back playing in July) is obviously less than ideal.
To compound matters, Chiefs loose forward and All Blacks vice-captain Sam Cane is in doubt for the Crusaders match due to an abdominal strain which has forced him to miss the last four matches. His last game was the Chiefs' victory over the Reds on April 21.
Cane is probably another player who could perform against France despite a lack of match fitness but Crusaders openside Matt Todd, not included among the seven loose forwards in the All Blacks squad, has likely been placed on standby.
It's a worse-case scenario but should Whitelock and the 53-test Cane be ruled out of the opening test then that's a lot of experience lost in one fell swoop, with fullback and vice-captain Ben Smith likely to be given full captaincy duties. Crusaders and All Blacks midfielder Ryan Crotty is another hoping for an all-clear from concussion this week.
Hansen named only three locks in his squad – Whitelock, Brodie Retallick and Scott Barrett. Another Crusader, Luke Romano, who played 24 minutes off the reserves bench in his side's win over the Hurricanes, will probably come into the frame should Whitelock not recover in time.
Whitelock, inspirational for the Crusaders on their march to the title last year and in similar form this season for Scott Robertson's team, was a bystander in Christchurch today as the All Blacks put their finishing touches on their last training camp.
He will be cleared only once he completes each "return to play" protocol. One of the last of those is training in contact situations so it must be said that him watching the All Blacks rather than participating means it doesn't look good for a return this weekend.
For Scott Barrett, almost guaranteed a test start if Whitelock is ruled out, it's a case of giving his Crusaders and All Blacks teammate some space at the moment.
"I'm not too sure where he's at," Barrett said. "I try to stay away from him … the last thing he wants is everyone asking him how's his head, how's his head. As a mate you feel for him and hopefully he's out there this weekend or whenever he's feeling right."