Wallabies all-time leading points scorer Michael Lynagh says of all Michael Cheika's playmaking options former ACT Brumby Matt Giteau was the one who had pressed his claims the best.
Lynagh also thought Matt Toomua helped "straighten up" the Wallabies attack when he played and he warned against the Brumbies flyhalf from changing his aggressive defence despite suffering another concussion.
The backline Cheika picks for next weekend's first Bledisloe Test against the All Blacks in Sydney will give an indication of his favoured No.10 and inside centre pairing.
Lynagh said Giteau's efforts against South Africa in the first game of the Rugby Championship had shown he hadn't lost any of his class since moving to Toulon in France.
He said Giteau could also be the solution to the Wallabies' goal-kicking woes.
"I think Matt Giteau, after a bit of an understandably slow start in that game against South Africa, towards the end he was looking pretty classy," Lynagh told Fairfax Media.
"Probably [he'll play] more at 12 - he's a second playmaker, he's a second kicker, he's just everything you want for a 12.
"He's very experienced, he understands the conditions and a lot of the players from over in the northern hemisphere.
"If you were to ask me which one of those guys has actually given his chances a bit of boost I would say Matt was probably the one."
Lynagh was in Canberra on Friday to promote his new book Blindsided, which is largely about his journey since suffering a stroke in 2012.
While concussion is a massive problem in world sport at the moment, Lynagh said there wasn't a link between his stroke and concussion.
Toomua is going through concussion protocols after getting knocked out against Argentina last week.
He's an aggressive flyhalf, who can also play at inside centre, and is known for the big hits he can put on in defence.
But Lynagh didn't think he needed to change the way he played as was simply unlucky.
"That's one of the reasons he's in there because his defence is very strong," he said.
"The attack seems to have worked a bit better when he's on the field, he seems to straighten it up a little bit better. He's a very good player and brings different qualities to the backline.
"You've got to be careful when you start changing the way people play because if they start to go in a little bit tentatively they start to get injuries as well. I think it's more a little bit of luck."
Meanwhile, the Brumbies have signed former Queensland Reds winger Aidan Toua on a two-year deal, while also re-signing lock Blake Enever and prop Leslie Leuluaialii-Makin for two years.
Scrumhalf Joe Powell will be part of the extended playing squad in 2016.
