Downs coach Johan Neeskens said his team's cup charge would not affect their title aspirations.
“This is one of the opportunities to win something else,” Neeskens said ahead of their cup opener at GWK Stadium.
“We have the Nedbank Cup and the league left, so we're going for both, but now our focus is the game on Sunday.”
The Powerlines side is coached by Cornelius Brandt - a fulltime police officer - and the majority of the players in the squad are unemployed, with only their football to sustain them.
Sundowns, conversely, will welcome the return of players from international duty after Bafana Bafana played to a goalless draw with Senegal in a mid-week friendly.
“We already had a different week because a lot of players were on national duty, but when they come back hopefully they return healthy," Neeskens said.
"For the rest, this is like any other week. We prepare ourselves every day in practice.”
Downs also face the prospect of playing in sweltering heat in Kimberley, but their Dutch minder was preparing accordingly.
“We practised at 3pm on Thursday, and on Saturday we also practise at that time," Neeskens said.
"It won't be the first game where the players play in very hot temperatures like you have in Kimberley.”
Veteran Surprise Moriri said the visitors expected a tough challenge from the little known Powerlines outfit.
“When I was playing for Silver Stars I really wanted to make a name for myself,” Moriri said.
“It's the same with the guys that we are going to be playing against, so they will go out there and really try and make things difficult for us.”
Moriri, however, warned that his team would be gunning for progression.
“We are taking this game very seriously and this is the only game that will take us through to the next round.”
Elsewhere this weekend, Mpumalanga Black Aces are at home to Witbank Spurs in a derby clash at Rand Stadium on Saturday afternoon, while African Warriors host premiership side Jomo Cosmos at Charles Mopeli Stadium.
Later in the evening, Kaizer Chiefs and minnows Cape Town All Stars meet at FNB Stadium, and Golden Arrows host NW Shining Stars at King Zwelithini Stadium.
SuperSport United are away to Batau FC at AJ Swanepoel Stadium, in Ermelo, on Sunday.