MADRID, SPAIN - MAY 04: Karen Khachanov of Russia server during his Men's Singles match, round of 64, against Kei Nishikori of Japan on the ATP Masters 1000 - Mutua Madrid Open 2021 at La Caja Magica on May 4, 2021 in Madrid, Spain (Photo by Oscar J. Barroso / Europa Press Sports via Getty Images)
