ATLANTA, GA - JULY 27: Mischa Zverev of Germany returns a backhand to John Isner during the BB&T Atlanta Open at Atlantic Station on July 27, 2018 in Atlanta, Georgia. (Photo by Kevin C. Cox/Getty Images)
ATLANTA, GA - JULY 27: Mischa Zverev of Germany returns a backhand to John Isner during the BB&T Atlanta Open at Atlantic Station on July 27, 2018 in Atlanta, Georgia. (Photo by Kevin C. Cox/Getty Images)