Japan's Kei Nishikori has expressed concerns about staging the Olympic Games in Tokyo this summer as Japan battles to contain a surge in Covid-19 cases.
"I don't know what they are thinking, and I don't know how much they are thinking about how they are going to make a bubble, because this is not 100 people like these tournaments," Nishikori said at the Italian Open in Rome on Monday.
"It's 10,000 people in a Village, playing a tournament. I don't think it's easy, especially (with) what's happening right now in Japan, it's not doing good."
ATP Indian Wells
Evans battles back to see off Nishikori challenge
- 'So much to think about' - Williams, Osaka unsure about Olympics
- 'Just like old times' - Murray and Djokovic have fun-filled practice
Nishikori, who won bronze in the men's singles at the 2016 Olympics in Rio, added that there was still time before a decision had to be made but was wary about the potential for an outbreak in the Athletes Village.
"You can make a good bubble and maybe you can do it," he said. "There is some risk too. What happens if there's 100 cases in the Village? Or it can be thousands."
'I need to figure out my next move' - Serena admits uncertainty about Tokyo games
The 2020 Olympics were postponed by a year due to the pandemic and organisers have stood firm in saying that the global sporting showpiece would go ahead this summer.
Several test events with foreign athletes have been successfully held, most recently on Sunday, but a visit by International Olympic Committee head Thomas Bach scheduled for May 17-18 has been cancelled.
ATP Indian Wells
Murray gets tricky Indian Wells draw with potential Alcaraz and Zverev tests
ATP San Diego
'I've had some tough draws' - Murray beats Kudla, to face Ruud in San Diego