Day 3 at the 2026 Australian Open delivers some amazing first-round action. Among them, Naomi Osaka's clash with Antonia Ruzic stands out as a real test.

The game caught the eyes of many, and this includes Serena Williams' ex-coach, Rennae Stubbs.

Stubbs, who coached Serena during her heartfelt 2022 US Open goodbye, got real on her podcast about why Osaka's not ready to lift the Daphne Akhurst Memorial Cup.

She pointed out Osaka's shaky United Cup prep. And also highlighted the loss to Maria Sakkari. "Look, she just doesn’t have the tennis under her belt that she needs coming in here," Stubbs laid out plainly. "Can she beat anyone on any given day? Absolutely. Naomi Osaka is a four-time champion of a Major title. She knows how to win them."​

Osaka has a favourable path in making it out of the first week at Melbourne Park. But from the round-of-16 onward, she could face the likes of Iga Swiatek, Elena Rybakina, Amanda Anisimova, and Aryna Sabalenka.

But Stubbs doubled down by adding more to it.  "I just don’t think she’s quite there enough to beat an Iga Swiatek or a Rybakina or any of these players. But then again, who knows? We know she’s capable. She has the tools, that’s for sure."

Osaka rolls in as the No. 16 seed, her first since 2022, against 20-year-old Croatian Antonia Ruzic in the opener.

Naomi Osaka Set to Steamroll Ruzic

Ruzic crashed out early at the 2025 US Open to Taylor Townsend in straight sets (6-4, 6-4). But then Osaka's built a legacy here too with titles in 2019 and 2021. She's reached the third round in six of her last seven AO years.

Though post-2021 Osaka struggled past that at Melbourne. After a strong 2025 US Open semi-final games and two wins at the Japan Women’s Open. But now Osaka's eyeing aggression to shake off her illness doubts. Osaka's a massive favorite, looks like a -800 odds.

And predictions lean straight sets under 20.5 games. Thus, the power should steamroll Ruzic's Slam inexperience in this Melbourne Park debut.​

Osaka should handle this no sweat, turning Stubbs' shade into fuel for a third AO crown chase. Ruzic's gritty, but Naomi's serve and big-match savvy scream quick W, tune in Tuesday for the vibe check.

Written by

Ishika Ghosh

Edited by

Oajaswini Prabhu