Naomi Osaka is the game’s in-form player, riding a 21-match winning streak. Ash Barty is the tournament’s defending champion and top seed.
They are the world’s top two women and find themselves on course for a highly-anticipated clash in the Miami Open final.
But there is no guarantee that this will eventuate, given the strength of opposition that they could face en route to finals weekend in Florida.
Unlike the men’s tournament in Miami, from which there have been several high-profile withdrawals, the women’s field at Hard Rock Stadium boasts 19 of the world’s top 20.
The only absentee from that bracket is seventh-ranked Serena Williams.
Osaka, the reigning Australian Open champion, said she was not surprised by the depth of talent currently characterising the women’s game, which in 2021 has seen 11 different winners from 12 WTA tournaments.
"I feel like everybody that you see doing well right now, you could kind of see it coming,” said Osaka, who opens her campaign against Australian Ajla Tomljanovic.
DRAW: Miami Open women's singles
“For example, like (Jennifer) Brady, I could see that she was going to do well and sort of start going deeper in the draws. (Garbine) Muguruza, she's won two Grand Slams, it's not very surprising at all (to see her succeeding).
“The level of women's tennis has really risen. From the outside people might say it's really random and whatever, but I think it's just so strong, so everyone has a chance to win."
Brady, the world No.14 whom Osaka beat in the AO final, is positioned for a last-16 meeting with fourth seed and AO 2020 champion Sofia Kenin.
Kenin, who has not played since undergoing appendix surgery in Melbourne, said she had shrugged off the nerves which plagued her during her AO title defence.
“I think it kind of took a toll on me,” she admitted. “But it was a month-and-a-half ago so it doesn't matter what was there. We're now, and I'm just going to do everything I can to handle my emotions.”
Muguruza, the recent Dubai victor who leads the tour with 18 match wins in 2021, could meet another major champion, No.8 seed Bianca Andreescu, in the fourth round.
It was in Miami in 2019 that Andreescu suffered one of her many injury setbacks; a shoulder problem forced her retirement from her fourth-round match, ending the 10-match winning streak she had built following her Indian Wells victory a fortnight earlier.
"I'm doing really, really good,” the Canadian said of her physical health.
"I guess there is some doubt always in the back of my head, but I'm trying my best to get rid of that. It's not easy, it's a process, but I'm working a lot on that.
"I'm the type of person to always set high expectations for myself ... but now my main goal is to just be happy out there. Even if my tennis feels off, I just want to take it as something I can push through and feel fulfilled at the end after the match.”
Stacked draw
Also among the 96-player field are world No.3 Simona Halep, powerful seventh seed Aryna Sabalenka, two-time major champions Petra Kvitova and Victoria Azarenka, and reigning Roland Garros winner Iga Swiatek.
Kvitova, Sabalenka and Swiatek are also WTA tournament champions in 2021.
And then there’s Barty, who first faces a qualifier in her first event outside of Australia since winning the WTA Finals in Shenzhen 16 months ago.
The world No.1 revealed that, due to flight cancellations, it took her almost 50 hours to reach Miami, where she won the most recent staging of the event in 2019 with a win over Karolina Pliskova in the final.
"It was quite hard to leave Australia, and quite emotional. But we're excited to have the opportunity to play the whole season,” said Barty, who did not compete for most of 2020 due to the COVID-19 pandemic.
“I think we're looking at staying away the whole season. We can't plan too far ahead – as we know, everything can still change so rapidly, but we're planning as best as we can.”
Should the WTA confirm that points earned at the 2019 Miami event will drop off after the 2021 edition, Barty’s top ranking could be vulnerable to Osaka, who would have to earn 416 more points than the Australian this fortnight.
It would mark Osaka’s first time at the summit since September 2019; Barty has been there ever since.
"She's certainly on an exceptional run and she knows that she can bring her best at the biggest tournaments,” Barty said of Osaka.
“That's what we all strive to do, and she's doing it the best at the moment I think.”