INDIAN WELLS, CA - MARCH 16: Alexander Zverev of Germany returns a shot to Rafael Nadal of Spain during the BNP Paribas Open at the Indian Wells Tennis Garden on March 16, 2016 in Indian Wells, California. (Photo by Matthew Stockman/Getty Images)
INDIAN WELLS, CA - MARCH 16: Alexander Zverev of Germany returns a shot to Rafael Nadal of Spain during the BNP Paribas Open at the Indian Wells Tennis Garden on March 16, 2016 in Indian Wells, California. (Photo by Matthew Stockman/Getty Images)