Christian Lealiifano and Sam Carter will split the Brumbies' captaincy duties in 2018, with new coach Dan McKellar electing to stick with the tried and trusted duo.

The pair were unveiled as the club's leaders at the start of 2017 but with Lealiifano spending the majority of the year inspirationally fighting his battle with leukaemia, Carter took the reins on field.

McKellar saw no reason to change that combination and said it was an "easy decision" to make, despite the return of David Pocock to Canberra.

"They're two guys that are highly respected throughout the group, two guys that have developed as leaders over the last 12 months," McKellar said.

While they will both have the "C" next to their name on the team sheet, Lealiifano will take the reins on field. Outside of that, the pair will split all off field duties, a setup McKellar feels particularly comfortable with.

"Christian has been in the role a few years now," the rookie coach said.

"Obviously he did the role with Stephen Moore in 2016 but I think with Carts, the way he has carried himself over the last few months - led by example with his actions in preseason and the way he has applied himself - I think he has learnt a lot in doing the job last year."

"It was a pretty easy decision, to be honest."I had probably decided by early January."

Lealiifano said the nod was a "special one" after leading the club as best he could behind the scenes last year. "Obviously it has been well publicised that it has been a massive journey and I guess this is something that makes me really humbled and really proud," Lealiifano said.

"It was a difficult situation last year but it was really special to still be named a leader - even though I wasn't around the place.

"Even the new guys in here now that are still supporting me - it's special."

Carter was thrown into the furnace in 2017 and said it was the work of Lealiifano behind the scenes that allowed him to prosper.

"I got thrown into the role and I felt really comfortable," Carter said.

"I felt I had a really strong group around me.

"I believed in the group, I believed in the system and I believed in what we were doing down here.

"We didn't have the greatest season ever last year but we put our best foot forward, really tried, got to the finals and this year, we want to build on that."

The Brumbies take on the Rebels in Queanbeyan on Saturday, kicking off at 6pm AEDT, streamed LIVE on brumbies.com.au.