Their Super Rugby season at stake, the wounded Waratahs are bracing for a torrid Australian derby against the Brumbies at ANZ Stadium on Saturday night.

The Waratahs must beat the ACT side to secure a playoff berth, but are likely to be without powerhouse forwards Wycliff Palu (shoulder) and hooker Tatafu Polota-Nau and likely also centre Berrick Barnes, who continues to struggle after a series of head knocks.

Fears surfaced on Sunday that Palu had suffered a bone fracture late in Saturday night's impressive 33-7 win over the Highlanders and he and Polota-Nau will both learn their fate on Monday.

Polota-Nau also had scans after suffering a possible posterior cruciate ligament tear - but to the opposite knee he damaged in the same manner earlier this year.

"It's a big week coming up and it's really important that we freshen up. Some of the guys are pretty sore and battled through really hard," NSW captain Phil Waugh said after making a successful comeback from a hamstring tear.

"There were some pretty big individual performances out there to keep turning up."

Despite the mounting injury toll, the Waratahs were maintaining a brave front and believe they can cause some damage in the playoffs if they make it for the fifth time in the past seven years.

"It's the last roll of the dice next week but going into finals, it's good to have that pressure to perform," Waugh said.

"With this team, if we deserve to be there, we'll get there. That's the reality of this competition. There's no favours to be had.

"And when we get there, if we do get there, I think we'll be in a pretty good space having had those two do-or-die games going into it."

Coach Chris Hickey said having the Brumbies stand between the Waratahs and a finals spot was a fitting climax to the home-and-away campaign.

"I think the derbies have been one of the features of this Super Rugby competition and we know we're in for a very tough game next week with the Brumbies and it's become one of the traditional clashes in Australian rugby," he said.

"They're not going to come up the highway to do us any favours. We know that we've got to get out there and earn every single point that we can take."

Hickey said Barnes would undergo more tests during the week after lasting just 35 minutes against the Highlanders.

"It's just this migraine issue again," Hickey said.

"He didn't take a knock or anything. He just started to feel ill and we just felt that was probably a sign that it was the right time to get him out of the game rather than risk them.

"It's just an exertion thing. It's got nothing to do with a head knock at all. This is what the neurologist is trying to explain to everybody.

"So they're just trying to pinpoint what it is with Berrick."

If Barnes is unable to play, Hickey was hopeful that Ryan Cross will have recovered sufficiently from a knee injury to take his place in the centres alongside Saturday night's hat-trick hero Tom Carter.

Brought to you by AAP © 2024 AAP