Like the fresh-faced youngster barely out of his teens who met the Queen on his first Wallabies tour, Matt Giteau is approaching his 100th Test milestone with good humour and a twinkle in his eye.

Outwardly, Giteau – like captain Stephen Moore, who will also play his 100th Test in this Sunday’s quarter-final with Scotland – has been eager to deflect the attention away from himself and towards the win-or-go-home Rugby World Cup match at Twickenham.

He’s been singing from the same hymn sheet as the coaching staff, too.

As special as they are, milestones won’t win you a game, says Wallabies’ assistant coach Stephen Larkham, who boasts 102 Tests.

But behind closed doors, Giteau’s playful side comes out as he tries to lighten the mood and break up the monotony of a lengthy World Cup campaign.

“It’s called ‘the Hundy week’, so if Gits asked for anything, he gets it,” good mate and veteran winger Drew Mitchell explains.

Like when he asks five-eighth Bernard Foley to sort out his breakfast order – “I will have porridge with banana, oats and raisins” – or by claiming a coffee when it is plonked on the table by a teammate.

“He is kind of now taking the piss a little bit,” Mitchell laughs.

“That’s how he’d prefer it – to approach it more on the jovial side and try and brush away any accolade about it, or seriousness about it.

“That’s kind of the way he likes to go about it.

“But again, speaking to him and knowing him as I do, it is something he will look back on as opposed to rubbing it in our faces.”

Giteau knows the emotions involved in playing in a milestone match – he’s been part of Wallabies teams for the 100th Tests of Larkham, George Smith and George Gregan.

On all those occasions, he explains, the guests of honour were embarrassed by having the spotlight shone on their achievements.

“The players will play them down, and so they should because it’s a team sport and you want to chase that team success,” Giteau told AAP.

“But as a player, you don’t want to let that guy down. That’s how I felt, playing for those guys.

“You really want to put in a good performance,” he said before cheekily adding “and I don’t want to put pressure on the other guys but, if they don’t play well, I’ll probably never speak to them ever again.”