Kei Nishikori will skip the upcoming Golden Gate Open tennis tournament as he continues to deal with a knee issue, the Japanese former world No. 4 announced Thursday on social media.
The 33-year-old, who had hip surgery in January 2022, considered playing the tournament in Stanford, California, on the ATP's secondary Challenger Tour from Sunday in preparation for his planned Grand Slam comeback at the U.S. Open, which starts Aug. 28.
Nishikori had already chosen to sit out the recent Citi Open and the ongoing National Bank Open due to the issue with his left knee, which he had heavily taped while making his ATP tour return at the Atlanta Open late last month.
"Unfortunately will not be able to play the Stanford Challenger next week," Nishikori wrote. "My knee is not 100% healed yet. I want to thank the tournament for the offer and I will continue to work hard to get back on tour."
Nishikori is named on the men's singles entry list for the U.S. Open in New York, where he played his most recent Grand Slam in 2021.