Carter was disappointed at missing Wallabies selection but said being in Europe for the Barbarians Wembley Stadium showdown with South Africa at the same time as the national squad was a "great opportunity".

The Wallabies have won just three games from 10 attempts in 2016 and with a revolving door of lock combinations Carter hoped it would be a case of being in the right place at the right time.

Carter was unsure if Cheika was behind his Barbarians call-up but said it would rank as a career highlight nonetheless.

"Maybe [Cheika] short-listed a bunch of players that he wanted on tour, and that he wanted to be in Europe but I can't be completely sure about that," Carter said.

"It's more of an experience as well, getting to represent the Barbarians. Not many people get to do that in their career and I think it's a great opportunity for me to do that.

"It's definitely something I wanted to do before I finished my career and to get the opportunity now seems pretty perfect timing."

Being summoned into the national squad wouldn't be a first for Carter, who was based in Bordeaux in the opening stages of last year's World Cup before being called into the Wallabies squad

"I've done it before and I'm hoping that I can just play consistent enough at the Barbarians that I can get a crack," Carter said.

"When you play rugby you want to be playing the highest level. The Wallabies' 30-man squad was my goal. Missing out was disappointing but you take the opportunities when you get them."

Following the tour Carter will shift his attention to "a transition year" with the Brumbies searching for a new coach, playmaker and chief executive.

Carter said "it was tough" to digest the news of Stephen Larkham's post-2017 departure, when he will take up a full-time role with the Wallabies.

"Obviously he's been associated with Canberra for a long time and he's given everything to the Brumbies over the last couple of years," Carter said.

"He had to make a decision on what was best for him and his family. I think moving on to the Wallabies with the ultimate goal to coach the Wallabies one day is something he had in mind so that's the decision he went with."

Carter praised Larkham's early decision, which gives the Brumbies an extra 12 months to find a head coach for 2018.

"We'll still have Bernie [Larkham] next year ... I'm looking forward to playing next year and I'm sure we'll find a good replacement heading into the 2018 season," Carter said.

"We've lost a lot of experience — Stephen Moore, Matt Toomua, Bruzzy [Christian Lealiifano] — a few players leaving.

"But I'm sure there's a lot of young talent coming through. We've always developed our own talent here in Canberra, so I'm excited to see some of the new guys next year."

The Barbarians play South Africa on November 5 before and Fiji on November 11.