An ankle injury might have curtailed the second half of Matt Toomua's season, but former Wallaby Rod Kafer thinks it might have given the ACT Brumbies playmaker the jump on his teammate, Christian Lealiifano, for the gold No.12 jersey.

But Toomua and Wallabies backs coach Stephen Larkham felt Michael Cheika's preference for a playmaking inside centre meant it didn't matter where the pair had been playing.

Barring injury, the Brumbies have generally used Toomua at flyhalf, with Lealiifano wearing No.12, but Toomua's ankle problems have meant Lealiifano spent the last couple of months at No.10 instead.

Larkham then brought Toomua back at inside centre for the last few games of the season in a bid to keep his combinations intact.

Cheika has used Toomua and Lealiifano at No.12 in recent times for the Wallabies, preferring NSW Waratahs flyhalf Bernard Foley at No.10.

Kafer felt the Wallabies coach would stick to the Waratahs' combination of scrumhalf Nick Phipps and Foley and then possibly a Brumbies centres pairing.

At the moment that would be Toomua and Tevita Kuridrani and Kafer felt spending time in the Brumbies No.12 jersey could give Toomua the jump on Lealiifano.

Kafer said Toomua and Lealiifano played with a similar style and were "clear candidates" for the Wallabies inside centre job.

"Undoubtedly it does [help Toomua], there's no question about that. I think Bernard Foley is the bloke who Michael Cheika will pick [at 10]," Kafer said.

"One of the things that's important in a team is combination. I suspect Nick Phipps will be the scrumhalf, he's probably the form scrumhalf, although Will Genia has probably statistically had one of his best seasons.

"You look at Phipps and Foley, that's a combination that has been winning matchs and playing pretty well. Why would you break that combination up?

"And the combination of Matt Toomua or Christian at 12 with Tevita at 13, there's another nice combination in the midfield that would be popular from a selection perspective.

"One of the great mistakes [former Wallabies coach] Ewen McKenzie made this time last year was breaking up that combination and in the first Test he picked Kurtley Beale at five-eighth, who hadn't played there at all.

"I don't think Michael Cheika will make that mistake."

Toomua said if he was picked to play inside centre for the Wallabies then his time there for the Brumbies would obviously help, especially with the calibre of players he was up against.

The Wellington Hurricanes boasted All Blacks centres Ma'a Nonu and Conrad Smith.

But the 25-year-old said it didn't give him an edge over Lealiifano for the upcoming rugby championship or World Cup because he had previously played flyhalf for the Brumbies and then inside centre for the Wallabies.

"I think the fact that I did it last year is proof it's not really relevant since Cheik plays his 12s a certain way and he likes to play a ball-playing 12," Toomua said.

Larkham said a Wallabies squad would be selected and then the best combinations would be worked out from that to determine the starting XV. He said both Toomua and Lealiifano would be in that squad and then Super Rugby would be irrelevant after that.

Larkham agreed with Toomua that 10 and 12 were interchangeable and often did during the course of a game.

"The way we play there's not a lot of difference between 10 and 12 – they're both getting touches on the ball, they're both calling and the combination between them whether it's 10 or 12, sometimes it changes around on the field as well," he said.

"There's not a lot of difference there for them. The good thing for the Wallabies is that [Toomua] is playing again after being out for so long."