The Brumbies arrived in Cape Town on Monday knowing they need to win games against the Cape Town Stormers and Johannesburg Lions to ensure they don't tumble out of finals contention.

But they have to break a five-year drought in Cape Town and then aim for their best results from a South African tour in almost a decade to breathe new life into their campaign.

Wallabies prop Ben Alexander says the team will be driven by the "necessity" to win games away from home.

"It is a massive challenge, but I think we're in a good spot to do it because there is an element of necessity now," Alexander said.

"In past years we've come over to South Africa in a good position on the table and we've won a game and played all right.

"But now we have to [win]. We just have to, it's as simple as that. This is the first year for a few years now where we have to win. We're going to be desperate on this trip."

The Brumbies have lost four of their past six matches, including a devastating 13-10 loss to the NSW Waratahs in Canberra last week.

They have beaten just one side ranked in the top six, haven't won at Newlands, the Stormers' home ground, since 2010 and haven't won two games in South Africa on the same trip since 2007.

The Brumbies are still at the top of the Australian conference and second overall, but their ladder position is deceptive.

The Waratahs are just one point behind and have a game in hand, while the Brumbies could drop as low as seventh if they lose to the Stormers.

But confidence in the squad is still riding high and they will be bolstered by the return of scrumhalf Nic White, with playmaker Matt Toomua an outside chance of joining the team in Johannesburg.

"We've got the confidence we can win big games, we have done it before," Alexander said.

"It's a fine margin that gets you over the edge. We've lost to some really good sides … while we're not happy with how we've been playing, it's not a reflection of our confidence.

"We're disappointed, but we're excited about this trip. We've got big aspirations this year and that hasn't changed."

White is expected to return to the starting team to play the Stormers after missing the past three games with an ankle injury.

Lock Rory Arnold will also come into contention, while scrum coach Dan Palmer will double as the back-up prop for the tour.

Palmer, 27, retired last year but is making a cameo Super Rugby appearance while the Brumbies wait for Scott Sio and Les Makin to recover from injuries.

"The Stormers have a very good scrum and I think we're improving. Like everyone I think we're chasing consistency," Palmer said.

"We work very hard on our scrum, we've had some good performance and some shaky ones. We'll continue to work towards consistency."

SUPER RUGBY ROUND 13

Sunday: Cape Town Stormers v ACT Brumbies at Newlands, 1.05am (AEST). TV time: Live on Fox Sports 2