Serena Williams' return to professional tennis is looking increasingly uncertain, despite earlier hints that the 23-time Grand Slam champion might step back onto the court. The American legend hasn't played since her third-round loss to Ajla Tomljanovic at the 2022 US Open, and her longtime former coach Patrick Mouratoglou has now cast doubt on whether a comeback is truly in the cards.

While Williams had fueled speculation by re-entering the WTA drug testing pool and sharing training videos on social media, no official announcement has been made. Mouratoglou, who coached Williams for a decade, recently shared his thoughts in an interview with Spazio Tennis, revealing that even Serena herself may not know what the future holds.

"Serena, we are still in touch, of course we are. Is she going to come back? I don't know, I don't think she has taken the decision yet," Mouratoglou said. "I think she was happy to be super fit, happy to be able to practice and then it's a decision she will take or not. I cannot say, because I don't know. I don't even know if she knows."

The French coach emphasized that Williams' legendary competitive fire won't allow her to return unless she can compete at the highest level. "Serena will not come back to be number 20. If she comes back it will be to perform, so she will have to judge if she can perform or not at the highest level, and I guess this is how she's going to take this decision."

Mouratoglou's partnership with Williams began after her shocking first-round exit at the 2012 French Open. Together, they built one of the most dominant runs in tennis history, with 10 of Williams' 23 Grand Slam singles titles coming during their collaboration. The last of those victories came in 2017, when Serena defeated her sister Venus to win the Australian Open.

For now, fans will have to wait and see whether the GOAT decides to chase Grand Slam No. 24 or hang up her racquet for good. Either way, her legacy as one of the greatest athletes of all time is already secure.