MELBOURNE: After "the longest pre-season ever", world number one Ash Barty enjoyed the ideal preparation for her tilt at a maiden Australian Open title and the level of her tennis has surpassed expectations, her coach Craig Tyzzer said on Tuesday.

Home hero Barty did not play a competitive match for 11 months leading into the Australian Open warmup events but has now won eight straight matches and reached her third quarter-final at Melbourne Park.

"It's probably the longest pre-season we've ever had," Tyzzer, who began preparing Barty in October, told reporters.

"She's been playing well each match ... There's probably been a few dips and a few rises, so there's a bit of that flow as well.

"It's obviously great for us and for her. ... she's put it together really well, probably better than I expected."

Barty has not dropped a set in the Grand Slam, with two wins in front of crowds in the opening rounds and her last two at closed stadiums following a snap lockdown in Melbourne due to an outbreak of COVID-19.

She will play Karolina Muchova at an empty Rod Laver Arena on Wednesday, which is expected to be the last day of the lockdown unless the government extends it.

Barty was upset in last year's semi-finals by eventual winner Sofia Kenin in front of a heaving crowd but Tyzzer said the presence of fans would not put any additional weight on her shoulders as she bids to end Australia's 43-year wait for a home winner.

"I don't think so with Ash," said Tyzzer.

"I think she enjoys the Aussie crowd behind her. She's also good at going, 'OK, I have to focus on what's going on on the court.' It doesn't distract her.

"I think she's done that really well here."

Tyzzer said he had been "super impressed" with Muchova when she lost to Barty in the third round of the 2018 US Open, their only Tour meeting.

"It was a really high-quality tennis match. It was on an outside court with hardly anyone, about five people watched it," he said.

"I couldn't believe how good an athlete this girl was.

"She's (Barty) looking forward to playing against her. It's a great test because she is such a quality player, obviously improved out of sight from back then to where she is now."