Title defender Bianca Andreescu has reportedly withdrawn from this year's US Open amid concerns regarding the novel coronavirus pandemic. According to her, the current crisis has hampered her chances of returning from injury.

The 20-year old Canadian has not played a single game since suffering a knee injury at the WTA Finals last October. This year, the US Open is scheduled to be held behind closed doors at Flushing Meadows in New York. The tournament will start on August 31.

In last year's final, Andreescu had beaten Serena Williams. But this year, she won't be defending her title.

According to BBC, she said, "I have made the difficult decision not to return to New York this year. I have taken this step in order to focus on my match fitness and ensure that I return ready to play at my highest level. Unforeseen challenges compromised my ability to prepare and compete to the degree necessary to play at my highest level."

As per Andreescu, these "unforeseen challenges" include the unprecedented cancellation of events this year.

World number six Andreescu marked the fourth top 20 women's player to back out of the US Open. Before her, world number one Ashleigh Barty, along with fifth-ranked Elina Svitolina, and number seven Kiki Bertens, also pulled out from the tournament.

Bianca Andreescu wins the US Open 2019
Bianca Andreescu lifted her first Grand Slam title at the US Open 2019. Timothy A. Clary/AFP

According to the latest reports, world number two Simona Halep might also not play in this year's US Open. Amid such concerns, however, 23-time Grand Slam winner Serena Williams still plans to compete at the tournament.

When it comes to the men's event, world number one Novak Djokovic has confirmed his intentions of participating in the competition. However, the defending men's US Open champion, Rafael Nadal, has already pulled out due to the pandemic situation, although he is likely to play at the French Open, starting on September 27. The former world number one, Roger Federer won't participate, given that he is recovering from injury.

The United States of America continues to lead the global charts in terms of the highest number of COVID-19 positive cases. The country is headed towards the 5.5 million-case mark, with more than 170,000 deaths recorded already. With the number of new daily cases not showing signs of slowing down, there were criticisms regarding the US Open's decision to continue their event.