Ashleigh Barty Photo: VCG

World No.1 Ashleigh Barty is preparing to spend the rest of the season on the road as she prepares to defend her Miami Open title this week in her first overseas appearance since the pandemic.

The 24-year-old from Queensland elected not to travel outside Australia after the WTA Tour resumed last year, skipping both the US Open and the rescheduled French Open at Roland Garros in September.

However, with COVID-19 in retreat in several parts of the world, and authorities more adept at managing safety protocols, Barty has traveled to Florida for the first stop on what should be a grueling year.

The Aussie got a taste of international travel in the age of coronavirus when her journey to the United States ended up taking nearly 50 hours.

"It was a long one," Barty said Tuesday. "It was about 48 hours door-to-door. We had a flight cancelation leaving Australia, another flight cancelation when we got to LA. It was quite a wriggle around.

"Tough playing tennis after traveling again. Quite a while since I've done that. I'm looking forward to feeling good in another day's time."

Barty, who will face either Hailey Baptiste of the United States or Slovakia's Kristina Kucova in her opening game, said she is excited for the season ahead despite finding leaving Australia difficult.

"It was quite hard to leave and quite emotional to me," she said. "But I think we're excited to have the opportunity to play the whole season. We're looking at staying away the whole season."

The biggest threat to Barty's hopes of defending her 2018 Miami crown is likely to come from Japan's Naomi Osaka, who is also in the field in Florida.

Osaka is brimming with confidence after winning her second US Open title in September before backing it up with the Australian Open last month.

Barty, who exited in the quarter­finals in Melbourne, has controversially retained her No.1 spot despite Osaka's recent dominance due to the pandemic-adjusted rankings rules.

Asked to comment on Osaka's form, Barty revealed she had hardly watched the Japanese star - or any other player - during the last year.

"I don't watch a lot of tennis," Barty said. "I've probably seen all of 30 or 40 minutes of tennis over the last 12 or 13 months. It's not something that I ever flick on and watch.

"Having not played Naomi, either, it's hard for me to really comment.

"She's certainly on an exceptional run. She knows she can bring her best to the biggest tournaments. That's what we all strive to do."

The women's field in Miami was deprived of a star name on Sunday, when Serena Williams withdrew from the tournament as she recovers from oral surgery.

On court in early round games on Tuesday, elder sister Venus Williams crashed out at the first hurdle, losing 6-2, 7-6 (12/10) to Kazakhstan's Zarina Diyas.