Smith was confident incumbent offspinner Nathan Lyon and O'Keefe would be a potent force, having seen them bowl in tandem for New South Wales.
"They have bowled well together," he said. "Hopefully they can do that this week and he [O'Keefe] can press claims for the Sri Lankan tour. He has got an opportunity now to become the second spinner."
Australia haven't played two tweakers in a home test since legspinners Stuart MacGill and Shane Warne played together in 2006 at the SCG.
Rain is predicted to interrupt every day of the contest but that failed to sway the selectors away from O'Keefe.
"The wicket is quite hard and dry underneath," Smith said. "This wicket recently has been spinning off the grass."
Josh Hazlewood has been granted his wish of playing all six tests this summer. Team management have been worried about his workload and it is likely Hazlewood will be rested from a large part of Australia's five-match ODI series against India that follows the test.
"We've had a few conversations but at the moment we're just concentrating on this test," Smith said. "We'll cover that off after this test. We'll see how everyone pulls up."
Smith is nursing knee and hip niggles but has no intention of missing a game this summer.
If South Africa continue to struggle against England, then Australia will be within striking distance of the No1 test ranking.
Smith described grabbing that mantle as a "huge motivation".
"We're working extremely hard to get there," he said. "It'd be nice to win this week and wrap the series up 3-0."
- AAP