As most professional sports return following extended time off because of the coronavirus pandemic, tennis is still trying to find its footing. Nearly five months have gone by without a tournament, and the major championships will be missing several marquee names.

The U.S. Open is scheduled to start on Aug. 31 in Flushing Meadows, New York, but the sport’s top female player won’t be competing. Ashleigh Barty, the top-ranked women’s tennis player in the world, announced Thursday that she’s skipping the Grand Slam because of coronavirus concerns.

“My team and I have decided that we won’t be traveling to the U.S. for the Western and Southern Open and the U.S. Open this year,” Barty said in a statement to Australian media.

“I love both events so it was a difficult decision but there are still significant risks involved due to COVID-19 and I don’t feel comfortable putting my team and I in that position.”

The Western and Southern Open is scheduled to be held in New York from Aug. 22-28.

A week before Barty’s announcement, the Citi Open in Washington D.C. was canceled. The tournament was supposed to restart the ATP Tour.

“The international travel restrictions are the biggest things that aren’t resolved yet,” Mark Ein, chairman and CEO of MDE Tennis, operator of the tournament, told ESPN. “They’re complicated because they involve traveling to and from the U.S. So we were looking at a huge amount of the field that can’t enter the country or can’t get back home.”

World No.2 Simona Halep said last month she doesn’t plan to play in the U.S. Open. The Romanian player has also withdrawn from the Palermo Open on Aug. 3, citing anxieties regarding international air travel.

There are concerns that more top players could pull out of the tournament because of travel restrictions between Europe and the United States. It’s unclear whether all players that compete in the U.S. Open will be able to vie for the title at the French Open, which is scheduled to start on Sept. 27.

Fifth-ranked Elina Svitolina reportedly plans to restart her season at the French Open instead of in New York. Reigning U.S. Open champ Bianca Andreescu is not expected to defend her title.

World number one Ashleigh Barty has pulled out of the US Open
World number one Ashleigh Barty has pulled out of the US Open AFP / KARIM JAAFAR