It's why he still packs a pair of boots on game day, shifts nervously in his chair and almost puts his fist through the desk in satisfaction when the Brumbies score.

The Brumbies face a make-or-break clash against the Johannesburg Lions at South Africa's Ellis Park on Sunday. It will be the biggest test of Larkham's coaching career.

To get a taste of the intensity, Larkham invited Fairfax Media into his team's inner sanctum for last weekend's game against the Cape Town Stormers at Newlands.

It's quiet as the Brumbies are ushered on to the team bus, which is escorted by South African police for the 20-minute drive to Newlands.

Game day preparations began hours before. Players have had troubled joints strapped and Larkham has been delivering instructions at the team's hotel.

It's an eerie silence as the players switch on mentally for what's to come.

Players sit in the same seats every week, a hierarchical arrangement with experienced players at the back and rookies to the front.

Larkham whispers with assistant coach Dan McKellar in the front row, but none of the players flinch as supporters toot horns or bang on the side of the passing bus.

Rugby is more than sport in South Africa. At the stadium, the Brumbies arrive to a swarming crowd, five-deep stretching 50 metres. It's not much of a warm welcome.

Fowards Scott Fardy and Ita Vaea sit in their lockers and read the match-day program. Cover to cover, no doubt to preoccupy their thoughts.

Again, the players have assembled in their same order. It could be any dressing room, anywhere in the world, but the Brumbies players have their preferred place.

The team's Polynesian players are praying together.

Larkham is first onto the field, soaking up the atmosphere before going through kicking drills with half Nic White.

Larkham still doesn't wear a suit on game day, an oddity among Super Rugby coaches. He'd be running water and messages during the game if it was up to him, but Super Rugby's governing body, SANZAR, banned that idea.

"I don't see the point in wearing a suit. I'm still the backs coach, there's a role for me in terms of warming the boys up," Larkham says.

"You get a feel for the group, where the boys are at, when you're involved in the warm-up. You know if you need to say something."

When the players return to the rooms, Larkham's hands-on approach stops.

The noise grows, first the voice of vice captain White, then emphasis from skipper Stephen Moore.

Larkham sits in another room, changing out of his boots. He leaves to the coaching box, no need for a final word to his team.

"This is their time," Larkham says. "They know what to do, everything has been said."

Moore takes charge.

"We're specific in what we talk about, try not to make it fire and brimstone, but you need that element," the captain says.

"If you're standing outside the change rooms sometimes you'd think it was a crime scene. There's a lot of emotion and you can definitely feel that energy."

Larkham, McKellar, scrum coach Dan Palmer and performance analyst Trent Hopkinson are so jammed into the tight coaching box, the back legs of their chairs almost touch the rear wall. In front of each are laptops, notepads and radios linking them with on-field staff.

The Brumbies are desperate, they need to beat the Stormers to restore a buffer at the top of the Australian conference. But there's a calmness in the box.

McKellar and Palmer provide the aggression, Larkham - like he was as a player - is more composed.

"I try to keep that calm mentality, but it's not always like that," Larkham said.

"I try to make sure I'm thinking about what our options are, if you get too heated you get carried away in the moment and lose the bigger picture."

Larkham commentates on the plays under his breath. as if there is some telepathic message being transferred between he and flyhalf Christian Lealiifano.

The Brumbies lead 16-9. Larkham pulls his players together.

"Don't think about the score, get out there and have some fun," he says. "Score some tries, that's the way we want to play."

But the Stormers are taking the fun out of the contest. The home team is kicking their way to the lead, smashing the Brumbies' scrum.

"Tell Christian to get to our plays, stick to the plan. The one clear message is we have to fix up our discipline," Larkham relays to his sideline staff.

When David Pocock scores a try to put the Brumbies within one point with 10 minutes to go, there's silence.

It continues when Lealiifano misses the relatively simple conversion attempt which would have put the Brumbies ahead.

Larkham breaks it. He sends a message to his players, telling them to refocus. Stick to game-plan.

Post match

The Brumbies, beaten, trudge from the field. Their season hangs in the balance.

There's no paint-stripping verbal spray from coaches. Conversations are quiet, measured, even the chat between Larkham and Moore.

"It's certainly different, this is the first year I've had control of the program and I'm learning a lot," Larkham says.

"I'm learning the game from a different perspective. The most important thing to understand is that everyone is different and you have to find a way to have unity in the group.

"We've got work to do now. We know we're capable of winning."