Pocock was forced to pull out of Saturday's clash with Ireland with a back injury - with the Wallabies going to suffer a 15-6 defeat.
And although the 23-year-old openside has made a "massive improvement" in his recovery he could still miss the must-win game.
"We have to see how he comes along and improves over the next day or two," said Nucifora.
"At this point we're hopeful. If you saw him on match day last week and see him now - it's a massive improvement.
"But if there is any doubt we won't risk any of our players making something that is relatively minor into something major."
Australia need to beat the Eagles to keep alive their hopes of reaching the knockout stages following the loss to Ireland at Eden Park.
And Nucifora admitted that video analysis of the match had not made comfortable viewing for the squad.
"We know the areas we didn't perform as well as we should have in the match," Nucifora said. "We are going to have to improve in those areas.
"It was straightforward and there for everyone to see. We just have to get better."
Meanwhile Digby Ioane is definitely over of the USA game, with the winger admitting he is unlikely to return to action until the quarter-finals after breaking his thumb.
"It all depends on my rehab ... I don't want to get ahead of myself," Ioane said.
"Anything could happen with the next two games, but if we do make it I will definitely try to be there ... for the quarter (final) if we get there, but after last week's game it's going to be hard."
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