MILAN, ITALY - NOVEMBER 07: A general view inside the arena prior to the start of Day 1 of the Next Gen ATP Finals on November 7, 2017 in Milan, Italy. (Photo by Emilio Andreoli/Getty Images)
MILAN, ITALY - NOVEMBER 07: Daniil Medvedev of Russia warms up prior to his match against Karen Khachanov of Russia during Day 1 of the Next Gen ATP Finals on November 7, 2017 in Milan, Italy. (Photo by Emilio Andreoli/Getty Images)
MILAN, ITALY - NOVEMBER 07: Karen Khachanov of Russia returns a backhand in his match against Daniil Medvedev of Russia during Day 1 of the Next Gen ATP Finals on November 7, 2017 in Milan, Italy. (Photo by Emilio Andreoli/Getty Images)
MILAN, ITALY - NOVEMBER 07: Karen Khachanov of Russia returns a forehand in his match against Daniil Medvedev of Russia during Day 1 of the Next Gen ATP Finals on November 7, 2017 in Milan, Italy. (Photo by Emilio Andreoli/Getty Images)
MILAN, ITALY - NOVEMBER 07: Daniil Medvedev of Russia returns a forehand in his match against Karen Khachanov of Russia during Day 1 of the Next Gen ATP Finals on November 7, 2017 in Milan, Italy. (Photo by Emilio Andreoli/Getty Images)
