South Africa coach Peter de Villiers is hopeful that wings Bryan Habana and JP Pietersen will be fit for next Sunday's World Cup quarter-final against Australia.
De Villiers has already lost centre Frans Steyn from his plans due to a tournament-ending shoulder injury.
And having had to overcome second-row injury troubles earlier in the tournament, De Villiers will keep fingers crossed for no further setbacks.
"We are worried about our two wingers at the moment," he said.
"But I think this long week will give us sufficient time for them to get back on the field."
South Africa have arrived in the last eight by emerging unbeaten through the tournament's toughest pool, defeating Wales, Fiji, Namibia and Samoa.
Australia, in contrast, have had their problems, suffering regular injury setbacks and being knocked out of their stride by Ireland's stirring victory over them earlier in the competition.
But De Villiers added: "Their decision-making is really spot on, and then when they get turnovers they are really better than most teams in that they come from depth and they make yardage immediately.
"They force the width and they force the space around the field quite well.
"If they get it right, you are in for a long, long day. If you can shut it down, for them it's going to be a nice and equal contest."