Naomi Osaka’s China Open campaign came to an unfortunate end when she was forced to retire mid-match against Coco Gauff due to a back injury. After taking the first set, Osaka’s physical condition rapidly deteriorated. In a social media post following the match, the four-time Grand Slam champion shedded light on why she ultimately couldn’t continue.

“I locked my back up during practice earlier and honestly wasn’t sure if I could even play, but I just wanted to try,” Osaka shared on her Instagram story. “Unfortunately, things just got progressively worse during the match. Totally worth it though lol,” she added.

Osaka, who is testing new waters with her partnership with coach Patrick Mouratoglou, started strong and was leading by a set and a break, but Gauff managed to fight back and evened the score at one set each. As the second set went on, Osaka’s movement slowed, and she had trouble with her serve and shots. By the end of the set, which Gauff won 6-4, Osaka decided she couldn’t continue due to the pain.

Gauff, who had her own challenges coming into the tournament, showed concern for her opponent, helping Osaka off the court. “It was a good match up to this point,” Gauff said in the interview afterwards.

Naomi Osaka and Coco Gauff after the match (Lintao Zhang/Getty Images)

“I wish Naomi a speedy recovery. Nobody wants to win a match like this, especially at one set all. Overall, I tried my best. It wasn’t my best tennis. I don’t know, it was just one of those matches where you’re trying your best each point,” she said.

Gauff is trying a new collaboration

Osaka’s injury was the main focus, but Gauff’s recent coaching changes were also important. The 20-year-old recently split with Brad Gilbert, who helped her win her first big titles this summer, including Washington, Cincinnati, and the US Open. After losing in the fourth round of her US Open defense, Gauff decided to try a new coaching team.

Now, she’s working with Matt Daly and Jean-Christophe Faurel. This new setup seems to be working well, as Gauff earned solid wins over Clara Burel and Katie Boulter earlier in the China Open. She is now set to play against Yulia Starodubtsewa in the quarterfinals.