INDIAN WELLS, CA - MARCH 17: Kei Nishikori (JPN) in action during his quarter final loss to Jack Sock (USA) at the BNP Paribas Open played at the Indian Wells Tennis Garden, Indian Wells, CA. (Photo by Cynthia Lum/Icon Sportswire via Getty Images)
INDIAN WELLS, CA - MARCH 17: Kei Nishikori (JPN) in action during his quarter final loss to Jack Sock (USA) at the BNP Paribas Open played at the Indian Wells Tennis Garden, Indian Wells, CA. (Photo by Cynthia Lum/Icon Sportswire via Getty Images)