Finals come two weeks early for desperate Waratahs

The NSW Waratahs are pledging to fight fire with fire when their season goes on the line in Saturday night's must-win Super Rugby AU showdown with the Melbourne Rebels.

Anything less than victory at Sydney's Leichhardt Oval will consign the Waratahs to an enforced break before the international season begins in November.

With a last-round bye next week, the Waratahs will have no say in the matter if they lose to the Rebels and fall out of the top three.

Only three teams will make the finals.

But, so congested is the ladder, that the Waratahs - currently third and one point above the Rebels - can lock up a play-off spot with a bonus-point win this weekend.

"This competition, every game is pretty easy to get up for," Waratahs flanker Lachlan Swinton said.

"They're all derby games and against guys you know well or have played against previously.

"But for this game, we've both got heaps on the line - it's do or die - so we're all keen for it.

"It will be a great contest and we won't be taking a backward step, I know that."

Nor will the Rebels and Swinton knows that too.

"They have a couple of big bodies so it's going to be a big physical contest, which personally I'm excited for and I know all the lads are excited for that," he said.

"I know it's going to be a focus point for them and for us to shut that down will be important."

Swinton, who's proven somewhat of a revelation in the back row this season alongside Wallabies captain Michael Hooper, is well aware that this could mark his last chance to push for a national call-up for this year's Rugby Championship.

"But me personally and my team, we've got a job to do," he said.

"We can't think of that individual stuff. It's a team game and selections look after themselves."

While it's the last throw of the dice for the Waratahs, the Rebels will get another chance to move back into the top three if they lose.

They face the winless Western Force in the final round.