WASHINGTON, DC - JULY 27: Kei Nishikori of Japan looks on before a men's singles match against Shang Juncheng of China on day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)

WASHINGTON, DC - JULY 27: Kei Nishikori of Japan sits on the bench before a men's singles match against Shang Juncheng of China on day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)

WASHINGTON, DC - JULY 27: Kei Nishikori of Japan looks on before a men's singles match against Shang Juncheng of China on day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)

WASHINGTON, DC - JULY 27: Kei Nishikori of Japan sits on the bench before a men's singles match against Shang Juncheng of China on day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)

WASHINGTON, DC - JULY 27: Kei Nishikori of Japan during a men's singles match against Shang Juncheng of China on day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)

WASHINGTON, DC - JULY 27: Shang Juncheng of China returns a shot during a men's singles match against Kei Nishikori of Japanon day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)

WASHINGTON, DC - JULY 27: Kei Nishikori of Japan returns a shot during a men's singles match against Shang Juncheng of China on day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)

WASHINGTON, DC - JULY 27: Kei Nishikori of Japan reacts during a men's singles match against Shang Juncheng of China on day one of the Mubadala Citi DC Open 2026 at William H.G. FitzGerald Tennis Center on July 27, 2026 in Washington, DC. (Photo by Emilee Chinn/Getty Images)