“Carlos Alcaraz was a lost puppy with Rafael Nadal” – Serena Williams’ ex-coach skeptical of Emma Raducanu & Spaniard’s doubles partnership

Rennae Stubbs, former coach of Serena Williams, expressed skepticism about the high-profile mixed doubles partnership between Carlos Alcaraz and Emma Raducanu at the US Open, set for August 19-20, calling them the “weakest pair” and likening Alcaraz to a “lost puppy” during his 2024 Olympic doubles stint with Rafael Nadal, per Yardbarker. Speaking on her podcast, Stubbs remarked, “Carlos, I saw him play doubles with Rafa, and he was like a little lost puppy out there. Didn’t know where to hit the ball half the time or where to stand,” highlighting Alcaraz’s limited doubles experience despite his world No. 2 ranking and five Grand Slam singles titles, per The Tennis Gazette. She added, “Raducanu hasn’t yet reached a final since her 2021 US Open win. I don’t know how their doubles acumen will mesh,” per Yardbarker.

Alcaraz, who initiated the “Alcaranu” pairing by personally requesting Raducanu, has a 54% doubles win rate, including a 0-2 mixed doubles record at the 2023 Hopman Cup and a quarterfinal run with Nadal at the 2024 Paris Olympics, per The Tennis Gazette. Raducanu, world No. 36, has minimal doubles experience, with her first career doubles win alongside Katie Boulter at Queen’s in June 2025, per Tennis365. Despite Stubbs’ doubts, Alcaraz remains optimistic, stating, “I’ve known Emma for a long time. We’ll try to win, but it’s going to be really fun,” per The Guardian. X posts, like @TennisTalker, noted fan excitement for the pairing, while @SportsCritic22 echoed Stubbs’ concerns, per. The revamped US Open event, with its $1 million prize, has drawn stars like Jannik Sinner and Aryna Sabalenka, intensifying scrutiny on the duo, per BBC Sport.