Five Things To Watch For On Day 7

© 2017 Billie Weiss/BNP Paribas Open

Showdown on Stadium 1: Tracy Austin said it all: "It could be the best day of the year." The Tennis Channel commentator/two-time US Open titlist was talking about Sunday's BNP Paribas Open schedule in Stadium 1, a smorgasbord of a lineup that includes some of the best athletes ever ever to pick up a tennis racquet, all in one place, all in one day. The much-ballyhooed Group of Death -- the Slam title-filled quadrant that includes Roger Federer, Rafael Nadal and Novak Djokovic, gets into full swing.

It's Federer vs. Frenchman Stephane Robert; Nadal vs. Argentine Guido Pella; and Djokovic vs. Brit Kyle Edmund. But that's not all. World No. 5 Kei Nishikori will face Brit Daniel Evans, and a star-studded WTA slate includes reigning Roland Garros champ Garbine Muguruza vs. California upstart Kayla Day, and world No. 3 Karolina Pliskova vs. No. 5 Dominika Cibulkova. Whew! Now that's a hot ticket.

View Day 7 (Sunday) Order of Play

Return of Delpo: He's become one of the most popular players the game has ever known, a feel-good fan favorite/gentle giant who's been embraced on a global level like few players before him (as evidenced by his more than 2.7 million Twitter followers). From his maiden Grand Slam title at the 2009 US Open (where the towering, 6-foot-6 Argentine shocked Roger Federer in five thrilling sets) to his many wrist woes (he's had no less than FOUR surgeries at the Mayo Clinic), you just can't help but root for Juan Martin del Potro.

Del Potro

An Indian Wells runner-up in 2013, Delpo has played just six matches this year, and would love nothing more than to break through at the first ATP World Tour Masters 1000 event of the year. He'll open against countryman Federico Delbonis, whom he's never faced, on Stadium 2.

Team Bucie: The top-seeded American-Czech tandem of Bethanie Mattek-Sands and Lucie Safarova recently unveiled a newfangled celebratory dance. And why not? The righty-lefty combo has had much to celebrate of late. In January, they captured their second Australian Open title. It was their fourth major together (2015 French Open, 2016 US Open). On Day 7, they'll face Kiki Bertens/Johanna Larsson in Stadium 5. The colorful, fashion-forward Mattek-Sands, who captured mixed doubles Olympic gold with Jack Sock last summer in Rio, triumphed on these same courts last year with fellow American Coco Vandeweghe.

Mattek Sands Safarova
Read More: Five Minutes with Mattek-Sands and Safarova

Got Next? BNP Paribas Open ticketholders will catch an up-close-and-personal glimpse of the future on Sunday, as ATP World Tour Next Gen stars Nick Krygios, Alexander Zverev (pictured below) and Taylor Fritz strut their stuff at the Indian Wells Tennis Garden. The wildly talented and controversial Aussie Kyrgios, 21, who upset Novak Djokovic in Acapulco, meets Argentina's Horacio Zeballos. The 19-year-old German wunderkind Zverev took out three Frenchmen -- Jeremy Chardy, Jo-Wilfreid Tsonga and Richard Gasquet -- in winning his second career title in Montpellier last month. He faces Argentina's Facundo Bagnis. And Fritz — who at 19 has a ton on his plate and as a new husband and father -- brings his fluid, athletic ease to the court in a marquee matchup with 2014 US Open winner Marin Cilic, the world No. 7.

View Day 7 (Sunday) Order of Play

Sam vs. D-Young: All Sam Querrey has done in the last eight months is shock then-world No. 1 Novak Djokovic at Wimbledon and stun No. 6 Rafael Nadal in the Acapulco final only days ago. There aren't many secrets to the 26th-ranked Southern Californian's game: it's built around his 6-foot-6 power serve and a concussive forehand. What does remain a mystery is what motivates the American. His on-court body language can at times betray a certain nonchalance; while other times he looks like a true top-10 force. On Sunday in Stadium 3, he'll go head-to-head with 60th-ranked Donald Young in an all-American special. This will be a first: somehow, these two have never met at the ATP Tour level.