From allies to enemies, the Crusaders and Hurricanes will put their All Blacks friendships on hold this week for their final Super Rugby round-robin match and Steve Hansen will be watching closely to see who of his senior players will be selected after such a torrid Lions series.
The All Blacks coach hinted a day after the 15-15 draw at Eden Park which tied the series that he would like to think some of his Crusaders players might be rested from Saturday's match at Wespac Stadium ahead of their quarter-final a week later.
Skipper Kieran Read is an obvious player who needs to be carefully managed over the next few weeks, and his Crusaders teammate Sam Whitelock is another. Even hooker Codie Taylor, who started all three tests in the absence of Dane Coles and, like Whitelock, Owen Franks, Joe Moody and Israel Dagg, played against the Lions in Christchurch four weeks ago, will need to be monitored.
All of which puts Crusaders coach Scott Robertson in a tricky position. Robertson's twin priorities are obviously player welfare but also topping the points table after the round-robin in order to qualify for a home final should his team get that far.
At the moment the Crusaders are leading by two points over the Johannesburg-based Lions. If Robertson's men suffer their first loss of the season against the Hurricanes in Wellington, and the Lions beat the Sharks at Kings Park on Sunday morning, then the Crusaders face the prospect of travelling to Ellis Park for the final.
The Hurricanes are currently fifth, one point above the Chiefs, and would like to stay there in order to play a potential quarter-final against the Brumbies in Canberra rather than having to travel all the way to Cape Town to play the Stormers.
Reinforcing the need for care from both Robertson and his opposite Chris Boyd is the fact that the Crusaders' 20-12 victory over the Hurricanes in round 12 in May was one of the matches of the season in terms of its intensity.
No10 Beauden Barrett will have to be looked after by Boyd, but the Hurricanes are lucky in that their forwards haven't had the battering that the Crusaders' pack have had in the series. Another plus is the fact midfielder Ngani Laumape and fullback Jordie Barrett are likely to be energised in the extreme by their performances at Eden Park.
"I don't think it's that physical that we can't recover from it," Hansen said a day after the third test when asked about the toll the series had taken on his players. "Our guys have pulled up [well] this morning, there's no one injured. Everyone's bouncing round.
"They're disappointed but they're in good nick and that's a tribute to Gilly [trainer Nic Gill] and [physio] Pete [Gallagher] and Doc [Tony Page]... and what they've been doing at their franchises.
"I'm sure the Hurricanes and the Crusaders are really looking forward to belting each other, but the smart play would be to have a look at who we need to play and who we don't need to play from a Super Rugby championship [perspective].
"That's where I think a mental break would be just as important as a physical one. The Crusaders for example - they've already qualified so they've got a little bit of room to move with. The Hurricanes probably don't have as much so we'll wait and see what they do. It will be interesting."
Crusaders hooker Taylor has already said of his motivation to prepare for the Hurricanes match, and the same is likely for fellow front-rowers Owen Franks and Joe Moody.
Robertson, who watched as his team lose a recent "friendly" against the Highlanders in Timaru, is going to need to have some important conversations with his players, and, potentially, Hansen.
Hard labour - busiest All Blacks over the Lions series (minutes played):
Israel Dagg (Crusaders) (240 for ABs + 80 for Crusaders = 320 minutes)
Rieko Ioane (Blues) (160 for ABs + 80 for Blues + 80 for Maori = 320)
Sam Whitelock (Crusaders) (229 for ABs + 80 for Crusaders = 309)
Beauden Barrett (Hurricanes) (240 minutes for ABs)
Brodie Retallick (Chiefs) (240 for ABs)
Codie Taylor (Crusaders) (217 for ABs + 50 for Crusaders = 267)
Kieran Read (Crusaders) (236 for ABs)
Owen Franks (Crusaders) (162 for ABs + 50 for Crusaders = 212)
Joe Moody (Crusaders) (162 for ABs + 50 for Crusaders = 212)
Anton Lienert-Brown (Chiefs) (207 for ABs)
Sam Cane (Chiefs) (202 for ABs)
Aaron Smith (Highlanders) (193 for ABs)
In case you missed it... Super Rugby is back
Friday, KO 7.35pm: Highlanders v Reds at Forsyth Barr Stadium
Saturday, KO 3.05pm: Sunwolves v Blues at Prince Chichibu Memorial Stadium, Tokyo
Saturday, KO 5.15pm: Chiefs v Brumbies at Waikato Stadium
Saturday, KO 7.35pm: Hurricanes v Crusaders at Wespac Stadium
Quarter-finalists as they stand:
Crusaders (1) v Sharks (8) at AMI Stadium
Lions (2) v Highlanders (7) at Ellis Park
Stormers (3) v Chiefs (6) at Newlands
Brumbies (4) v Hurricanes (5) at Canberra Stadium