Rafael Nadal, Dominic Thiem won't have coaches for Australian Open?

Tennis stars Rafael Nadal and Dominic Thiem will both be without their coaches at the Australian Open that gets underway on Feb. 8. 

As Reuters noted on Thursday, Nadal's coach Carlos Moya is not traveling to Australia because of the country's strict health and safety protocols that include a mandatory 14-day quarantine upon arrival.

"After speaking with Rafa, we have decided that I won't travel to Australia with the team," Moya explained via social media. "I will follow the tournament from home and will stay with my family, parents and kids due to the delicate situation that Spain is living with the virus. Best of luck to the team."

Thiem's coach Nicolas Massu tested positive for COVID-19 but is hoping to receive clearance to travel if he returns negative tests. Reuters added, though, that travel restrictions will likely prevent Massu from joining Thiem's team at Melbourne Park. 

Nadal, an all-time great, notched his 20th Grand Slam title when he won the French Open last October. Thiem was the runner-up of the 2020 Australian Open but won the U.S. Open later in the year. 

Also on Thursday, American Madison Keys announced that she will miss the Australian Open after testing positive for COVID-19. Three-time Grand Slam champion Andy Murray may also not be cleared in time to quarantine and compete in Australia because of a positive test. 

Meanwhile, American Sloane Stephens shared via Twitter that both her grandmother and aunt recently died due to complications caused by the coronavirus.