"The Olympic sprinter will have a few more milliseconds to counterpunch instead of inviting Osaka for lunch" - Rick Macci provides guidance to Coco Gauff amid serving crisis

The last few places in the quarter-finals are up for grabs, with two titans of the game ready to clash in what is touted to be a tight tussle in New York.

World number three Coco Gauff goes into the final Grand Slam of the year with the chance of leaving as the number one in the world for the first time in her career. Previously the number two, she is currently not playing her best tennis, but is still in the hunt for a second US Open title, and her third major.

From a possible future number one to a former number one: in her way stands Naomi Osaka, who is starting to find her best game again after a hiatus from the sport. She won her maiden Grand Slam at Flushing Meadows back in 2018, with a second title in the US coming two years later. Australian Open titles followed the US Open triumphs, but since her last major in Melbourne back in 2021, she has stumbled into a decline. She cited mental health problems after retiring from Roland Garros and skipping Wimbledon, which was followed by her becoming a mother in 2023, with her maternity leave beginning.

2025 has been her best year since returning to the tour, making a final in the Masters 1000 event in Montreal, being denied the title by the young talent Victoria Mboko. She has continued her positive form into the US Open, taking down Greet Minnen, Hailey Baptiste, and former world number eight Daria Kasatkina. All of this has culminated in a tie with Gauff.

Despite the ranking advantage, not everyone has faith in the American to produce what is needed to reach a third quarter-final at Flushing Meadows. Rick Macci, who has previously coached the likes of Maria Sharapova, Andy Roddick, Jennifer Capriati, and the Williams sisters, has stated his concerns with Gauff's serve - the main weakness which has blighted her since the Roland Garros title run.

Macci, who owns his own tennis academy, went on social media to share his opinions and offer advice to Gauff. On X, he wrote: “Coco has to be ready for Naomi munching and crunching on her second serve. Look for Coco to hit the 80 mph kicker on the first try, as Naomi will be back a little farther to reply. The Olympic sprinter will have a few more milliseconds to counterpunch instead of inviting Osaka for lunch.”

In 2025, Gauff has notched up more double faults than anyone, sitting on 320 before the start of the US Open. For comparison, Aryna Sabalenka and Iga Swiatek respectively boasted 122 and 175 double faults in fewer matches. These problems have led to her failing to win a single tie on grass and being dumped out early in Montreal and Cincinnati.

It is starting to become the norm when looking at Gauff's double-fault stats and laying eyes on double-digits. The highest she accumulated in one match this year came in her opening round tie at the Canadian Open against Danielle Collins, where she racked up a staggering 23 double faults, with her conceding 14 in her next round tie against Veronika Kudermetova, before being dumped out by eventual champion Mboko.

Ahead of the US Open, she made the audacious decision to bring in Gavin MacMilan as her new service coach. It has not made an instant impact, with her serve allowing Alja Tomljanovic to get close to defeating her in a classic opening round matchup. She would then get emotional after being broken by Donna Vekic, but recovered to win in straight sets. The best performance came in the third round with a victory over Magdalena Frech, with much better service numbers.

However, if she is not careful tonight, then Osaka will punish her. The second service is a huge weakness in Gauff's game, and if pounced upon efficiently, could lead to the American being knocked out of her home Grand Slam. However, if she does take Macci's advice, then she may be within a shot of reaching the quarter-finals.