Les Kiss has firmed as the frontrunner to replace Joe Schmidt as Wallabies coach after NSW Waratahs mentor Dan McKellar categorically ruled himself out of contention.

Kiss was already the favourite before Rugby Australia boss Phil Waugh on Wednesday said he was open to a candidate coaching both a Super Rugby Pacific side and the national team simultaneously.

The Queensland Reds boss now seems even more likely to take over after this year's Rugby Championship after McKellar made it clear, again, his priority and focus was solely on returning the Waratahs to past glories.

A former assistant under Dave Rennie and one-time favourite before Eddie Jones was reappointed for his ill-fated second stint in 2023, McKellar appeared taken aback when asked if he was in the mix to succeed Schmidt.

"Me? Mate, how many times have I got to answer this? No. No, I'm not in the mix for the Wallabies gig," he said ahead of the Waratahs' Super Rugby Pacific hosting of the table-topping Chiefs.

"I came back here to help rugby out in this country by helping NSW and the Waratahs.

"And I'm really enjoying it here, loving the challenge, loving the players, loving the staff. We've got a tremendous facility.

"I'm enjoying life in Sydney and that's my job. I've signed here for three years and it's going to take time but I think we're heading in the right direction."

Michael Cheika coached both the Waratahs, in their title defence, and the Wallabies, to a Rugby World Cup final, in 2015.

But while saying juggling state and country commitments wasn't impossible, McKellar says it's not appealing to him right now.

"It's a big ask," he said.

"I did it as a head coach at the Brumbies and then I was assistant (Wallabies) coach and, yeah, you certainly enjoy that four or five-week break at the end of the year. That's for sure.

"If it's not a long-term thing, I think it's doable (but) you wouldn't want to be doing it year after year after year.

"But is it a short-term possibility? Yeah, I think it can be done.

"But it's certainly a long season and I found that out for myself when assistant with 'Rens' and doing the Brumbies at the same point in time.

"There's plenty to juggle there, and it's a massive workload but it's doable being head coach of both. It takes up another gear again.

"So I wouldn't say it's not possible but it'll certainly provide its challenges."

McKellar's unequivocal lack of interest in the role leaves Kiss as the only obvious Australian option for the Wallabies job after Brumbies coach Stephen Larkham last week ruled himself out.

RA could look for a foreign coach but that ended in tears for Rennie and even fellow Kiwi Robbie Deans despite the long-time former Crusaders boss boasting the best record as Wallabies coach since the halcyon days of Rod Macqueen.