NEW YORK -- You would be hard-pressed to find a bigger Serena Williams fan than Naomi Osaka. The four-time major champion has embraced her fandom since Williams announced she would be stepping away from tennis after the US Open. 

"I watched her first match in Toronto before she announced it," Osaka told reporters on Saturday. "For some reason I just started crying because I felt it.

"Then she announced it the day later. I'm like, 'Oh, my God, this is what devastation must feel like.' It really is an honor just to keep watching her play."

Osaka was in the stands in Cincinnati as well, watching Williams as she faced Emma Raducanu in the first round. If it wasn't for Williams, Osaka said she would have never found tennis or be able to chart her path as a global sporting icon. 

"There's definitely been a lot of barriers that I'm sure she had to fight to break down," Osaka said. "We can now easily go through that because of her."

Osaka has faced Williams four times in her career. Along the way to two of her major titles, she faced the tough task of ending Williams' quest for her own record-tying 24th major title. The first came in the 2018 US Open final. The second came last year at the 2021 Australian Open semifinals.

"I just get really nervous around her," Osaka said. "It's really weird to idolize someone, then boom, you're just talking to them. I don't know. I feel stressed out. But she's really sweet. She's given me pointers sometimes. 

"I know she didn't call it a retirement, she called it an evolution, which I think is really cool. I feel like the term 'retirement' kind of means an end to something. But since she says 'evolution,' it means a continuing journey."

As Osaka keeps a close eye on Williams' progress through what is expected to be her final tournament, she has a tough journey herself. Osaka acknowledged she was feeling "anxious" ahead of her opening-round match against Australian Open finalist Danielle Collins. 

I feel like I would have lied a day ago or so and said that I was really relaxed," Osaka said. "But actually when I practiced today I felt very anxious. I think it's because I really want to do well because I feel I haven't been doing well lately.

"I don't know. It's tough. Of course, you don't want to lose in the first round of a Slam. I feel like I always do pretty well here. It's kind of taking the pressure off of myself, but it's always going to be there."

The 2022 season has been difficult one for Osaka, mainly due to injuries. There have been surges of form, as in her run to the final of the Miami Open. But draws and injuries have left her stalled at No.44. Twice she has drawn Amanda Anisimova early in a Slam. An Achilles injury left her struggling during the clay season and forced her out of the grass. When she began her hard-court season in San Jose, she drew Coco Gauff in the second round. It's been difficult to build momentum. 

"I think this year's really funny for me just in regards to last year," Osaka said. "But this is definitely the most physically, I don't even want to say 'injured,' but I've had way more niggles than I've had before in my career.

"I was telling Nana [her physio Natsuko Mogi] that maybe I'm getting old, maybe this is like the growing pains. But I would say it's something that's very frustrating but at the same time interesting because it made me feel like, 'Wow, I really want to be able to play again like back how I used to.'"

Osaka holds a 3-0 record against Collins and has won all six sets.

"She's a very big power player," Osaka said. "For me, I always feel like I have to be on top of it because, like, as soon as I hit a shorter ball or something, then she'll immediately be the aggressor.

"For me it is a tough match, but at the same time I'm kind of relieved I'm playing someone that I know because I could have easily played against someone I have no information on. That in itself is also quite tough."