An in-form Rafa Nadal will look to continue his unbeaten run this year as former women's No. 1 Naomi Osaka aims to begin her climb back to the top when the Indian Wells open kicks off this week.

Nadal's season was cut short last year due to a foot injury but the Spaniard has come roaring out of the gates in 2022, winning January's Australian Open for a men's record 21st Grand Slam title.

He followed that up by winning his fourth title in Acapulco last month and has not lost in 15 matches this season.

"Rafa Nadal is now 35-years-old and he's never had a start to the season like this one," Indian Wells tournament director and former player Tommy Haas said on a recent podcast.

"He's the guy to beat here, there's no doubt about it. And he obviously enjoys it here very much," Haas said of Nadal, a three-time winner of the Masters 1000 tournament.

As a bonus, while in the Southern California desert, Nadal will stay at tournament owner and billionaire Larry Ellison's private resort, Porcupine Creek Golf Club.

"He can play 18 to 36 holes of golf every day if he wants to," Haas said.

"He likes it there and wants to stay for as long as he can. If he's healthy, watch out."

His Serbian rival Novak Djokovic was placed into the tournament's draw on Tuesday despite his ongoing refusal to take the COVID-19 vaccine, which would bar the world No. 2 from entry into the country.

"Novak Djokovic is on the tournament entry list, and therefore is placed into the draw today," tournament organizers wrote on Twitter Tuesday.

"We are currently in communication with his team; however, it has not been determined if he will participate in the event by getting CDC approval to enter the country."

Swiss Roger Federer will not be at the tournament as he is still recovering from knee surgery, while a cadre of emerging stars will be eager to topple Nadal.

Chief among them is Daniil Medvedev, who enters a tournament as the world No. 1 for the first time, and big-serving Andrey Rublev, who won a title in Dubai last month.

Both players are from Russia but they will not compete under the name or flag of their country, a decision handed down by tennis authorities following Russia's invasion of neighboring Ukraine.

"There are a lot of guys knocking on the door but Nadal has got to be the favorite," Haas said.

Osaka's return

On the women's side, opportunity knocks for Naomi Osaka, who as a 20-year-old announced herself with a triumph at the WTA 1000 event in 2018.

From there she won four grand slams, became the world's highest-paid female athlete and sparked a conversation about mental health in sports.

But time away from the court after last year's U.S. Open has caused her world ranking to plummet and the former world No. 1 is now No. 78 and unseeded at the tournament.

"I've heard she's in a wonderful place, a much better space than she was last year, and that she's excited to get back out and competing," three-time grand slam champion Lindsay Davenport told Reuters.

Osaka, who fell in the third round at the Australian Open, will face an in-form Sloane Stephens in a first-round blockbuster Wednesday.

"That's a really tough one to start off with, and Osaka is going to have to be ready to go," Davenport said.

"I think she was a little disappointed with how Australia went and that she's pretty motivated, but it's going to take a lot of work."

Davenport predicted a big year for Osaka and said her powerful game translates well on grass.

"If I were on her team, I would put a focus on trying to get her to believe that she could win Wimbledon."

Osaka will not have to worry about facing world No. 1 Ash Barty or top-ranked American Danielle Collins after both players withdrew from Indian Wells due to injury.

Also missing will be the top seed and world No. 2 Barbora Krejcikova, who pulled out due to an elbow injury. Frenchwoman Alize Cornet will move into the reigning Roland Garros champion's spot in the draw.

The tournament, which is officially called the BNP Paribas Open, returns to its March date on the calendar after being canceled in 2020 due to the COVID-19 pandemic and being moved to October last year.

Full stands are expected at the Indian Wells Tennis Garden for what is sometimes referred to as the sport's "fifth major."