With one hooker suspended subject to appeal and another ruled out with a history of concussion, the defending champions will be forced to blood a 22-year-old who has never played 80 minutes of Super Rugby at the intimidating high-altitude fortress of Ellis Park this weekend.

They are scrambling hard. The team will seek updated medical advice on Tatafu Polota-Nau with a view to flying him over to face the Cheetahs in Bloemfontein next week. Returning second-rower Dean Mumm has flown down from England to restart his career in sky blue early, and the team left Sydney on Monday with second-rower Will Skelton still hopefully attached to the flight manifest, in case his two-week suspension for dangerous play is downgraded on appeal.

But for now it is the Hugh Roach show. With little hope that a successful appeal would put a useful enough dent in Tolu Latu's four-week ban, Roach will make his starting debut for the Waratahs after two seasons learning his trade as a front-row understudy.

"Unfortunately it's come under these circumstances but I'm going to take my opportunity and give it everything I've got and see what happens," said the Eastwood hooker, who made his provincial debut for Western Australia against the British and Irish Lions in 2013.

It was all going so well for NSW when the SANZAR citing commissioner killed their buzz in the early hours of Sunday morning.

They had disposed of the faltering but still mighty Crusaders in convincing fashion to pip the Brumbies at the top of the Australian conference, and had three challenging but winnable games ahead to clinch a top-two finish and its associated spoils - a week's rest and a home semi-final.

But the storm clouds rolled in with news the citing commissioner believed both Latu and Skelton had cases to answer for their 17th-minute tackle on Crusaders second-rower Sam Whitelock.

The Waratahs rejected a proposed three-week plea bargain for Latu because they believed and will argue on appeal that the tackle did not meet the foul play threshold.

On Monday afternoon the club's legal representatives dialled into the hearing via videoconference, pressed their arguments before South African judicial officer Robert Stelzner SC - noting that significant discussions between the three match officials during the game concluded a yellow card was sufficient - and waited for the outcome. There was disbelief when Latu was handed four weeks, two of which were added on for "deterrence", and Skelton two weeks.

After receiving the written decision on Tuesday morning, the Waratahs have 48 hours to lodge their appeal, meaning a hearing before a three-person panel would be heard on Thursday evening at the earliest.

Waratahs chief executive Greg Harris said Polota-Nau would not be rushed back for this week's game, but could be flown over in time to face the Cheetahs.

"There's no way he will be considered unless he has 100 per cent clearance from the specialist," Harris said.

"The decision was made that he would not go to South Africa at all because it meant he could have an extra week's rest. It was purely at our discretion. If this week's tests say he's not right we won't play him, the player's health and welfare are the most important considerations in the game. But if he gets clearance to play we'll be forced to consider it."

In the meantime, Roach will lean on all of the experience his Test-capped teammates can offer in preparation for the biggest game of his promising career, while Manly hooker Dave Porecki has been drafted in as back up.

The Lions lie in wait, having quietly crushed any early expectation they would be the competition whipping boys in their second season back in Super Rugby.

"It's a definite hiccup, considering injuries [Polota-Nau] have been coupled with that in certain positions," No.7 Michael Hooper said. "But we get through this well and we have guys coming back and bursting at the seams to get ready and get on the field again. If we get through it, the wheels and the momentum will certainly be going strong."