"When I spoke to them about doing the role, they were both very excited. It's a massive workload so to share the job makes sense."
It's a routine that has worked well for the Chiefs in the past, as a combination of Messam and Craig Clarke delivered a couple of championships, while Cruden also co-captained alongside Messam in 2014.
So while Rennie had plenty of choice when reintroducing the leadership scheme - with Michael Leitch, Charlie Ngatai and Brodie Retallick appealing as alternatives - Cruden and Cane made the most sense for the coach.
"Aaron has a fair bit of experience in leadership for this group," Rennie said. "He's demanding - that's what I love about Aaron. He's got massive expectations of himself but also of the guys around him.
"He's not scared to wag his finger and demand. But he and Sam are both very good at understanding when to put an arm around someone. While they're challenging, they've both got empathy and they're good people."
The duo's leadership will be especially important for a young Chiefs team, shorn of Messam, Sonny Bill Williams and a host of outside backs who departed in the off-season.
Cruden and Cane have 121 caps combined to their names and the first five is mindful that, having turned 27 today, he's now an elder statesman in the team.
"Heading into my seventh year of Super Rugby, I'd like to think I'm relatively experienced," Cruden said. "And with a lot of new faces, I guess that's going to be important, how we lead and how we make the transition as smooth as possible."
There was another important aspect that was on Cane's mind. At 23, he is the younger of the pair, but boasts some pretty impressive recent captaincy experience after leading the All Blacks against Namibia at the Rugby World Cup.
One of the biggest lessons the flanker gleaned from that game was surrounding his communication with referees and, with Cruden hardly a stranger to chirping in the whistle-blower's ear, Cane was keen to defer to his good friend in that regard.
"You can lead on the field without being captain but, when things aren't quite going your way, or your might be getting frustrated as a player, you can't afford that to creep into your voice when you're talking with referees," Cane said. "You're trying to get the best out of each other and work to have a good game, so that's something that will develop.
Or maybe I'll just send Aaron in."
And how did Cruden feel about that plan? Who did he expect to be the biggest talker?
"Potentially myself," he said with a smile.
