Wells and Tom Staniforth have been given the job of impersonating hulking Cape Town Stormers veteran Schalk Burger during training this week in preparation for a Super Rugby showdown on Sunday.

It's part of the club's weekly preparation to have reserves take on the role of the opposition and present different situations to the starting line-up.

The unbeaten Brumbies are aiming for their fourth consecutive win, which would make it only the second time since 2011 that they have begun a season this way. Coach Stephen Larkham has resisted the temptation to make any changes.

Wells has joined the squad and is waiting to make his Super Rugby debut. The former Australian sevens player says he's ready for whatever opportunity is thrown at him.

"Training-wise, whenever it comes to an opposition back-rower, I tend to take that role in training to give the guys something to practise against," he said.

"Tommy Staniforth had [Burger's] role a little bit this week, he wanted to be a ball-player.

"It's nice to know that an opportunity could come my way and it's humbling to be called into a group like this when we're three from three to start the season.

"It's a good feeling and a bit daunting at the same time knowing that you've got to step up to the mark very quickly, but if I get the opportunity I think I'm ready. I've put in the hard yards and hopefully I can get there."

Wells was called into the Brumbies touring group, but has been left out of the game-day 23-man squad to play the Stormers as Larkham sticks with the combination that beat the Western Force last weekend.

It's the first time this year the Brumbies have managed to keep all 23 players together for two weeks in a row.

The squad was split over three different flights to South Africa – the back-line players were training in the gym of AFL club Fremantle Dockers last weekend.

"A South African travel week is always tough ... we will only have three training sessions as a team so there's not a lot you can do," Larkham said. "It's great to have the ability to run the same team out there and know the combinations are experienced together.

"The guys not in the starting team are making it very difficult not to change things up, but the boys have been playing well and their attitude has been spot on.

"It's a journey that the whole squad is going through this year, everyone is contributing whether they're starting, on the bench or in the squad. For this week, it makes sense to keep the same team on the field."

Back-rower Wells is working with David Pocock, Scott Fardy and Jarrad Butler to edge closer to his first game since making the switch from the sevens program to Super Rugby.

Wells played for Australia at a sevens tournament in Port Elizabeth last year, but is confident his transition is on track.

"Everyone has a lot of belief in the group that we've put in the hard yards and personally, if I was to get picked, it shows the coaches have confidence in me and that gives me confidence," he said.

"The strength of the team is that if you're not ready, you won't be picked. It's different coming back [to South Africa] for Super Rugby in terms of your preparation. There's a very strong vibe around the group that we can do the job we need to do."

Butler gets another crack at No.8 as Ita Vaea remains in Canberra to recover from a dislocated finger.

The Brumbies have beaten the Stormers in Cape Town just once in the past six years, and are one of only two unbeaten sides so far this season.

"We've found three different ways to win in the last three games," Larkham said. "This game will pose its own challenges for the team when they get out there.

"Things have worked out pretty well for us so far, but I'd expect teams to find their groove now.

"It's pretty evident the Stormers are trying to throw the ball around a bit more, but they've still got one of the best defensive records so we're certainly aware of that."

SUPER RUGBY ROUND FOUR

Sunday: Cape Town Stormers v ACT Brumbies at Newlands, Cape Town, 4.15am. TV time: Live on Fox Sports 2.

Brumbies team: 15. Aidan Toua, 14. Henry Speight, 13. Tevita Kuridrani, 12. Matt Toomua, 11. Joseph Tomane, 10. Christian Lealiifano, 9. Tomas Cubelli, 8. Jarrad Butler, 7. David Pocock, 6. Scott Fardy, 5. Sam Carter, 4. Rory Arnold, 3. Ben Alexander, 2. Stephen Moore, 1. Scott Sio. Reserves: 16. Josh Mann-Rea, 17. Allan Alaalatoa, 18. Les Leuluaialii-Makin, 19. Tom Staniforth, 20. Jordan Smiler, 21. Michael Dowsett, 22. Robbie Coleman, 23. Nigel Ah Wong.