The eyes of the world were on Naomi Osaka when she lit the Olympic flame on Friday night and it will be the same on Sunday when she ends her eight-week break from tennis by taking on China's Zheng Saisai.

Any doubt about Osaka's status in Japan or the sporting world in general was put to bed as she took the torch on its final journey in the Olympic Stadium, climbing a symbolic Mount Fuji in a striking ending to the opening ceremony.

Now the 23-year-old must turn her focus back to the court, where she has not been seen in a competitive environment since withdrawing from the French Open in May and opening up about her mental health struggles.

"Naomi Osaka is a great champion that we have in our sport," said Djokovic. "Playing in her country without a crowd is obviously not ideal for her, I'm sure that she wanted to have support and people behind her.

"She and (Kei) Nishikori carry a lot of responsibility and weight on their shoulders for sure playing in Japan, I know people expect a lot from them.

"But, even though Naomi is relatively young, she's a grand slam champion and she has quite a lot of experience playing at the highest level, so I don't think that's going to cause a lot of trouble for her."