Roger Federer, of Switzerland, returns a shot against Steve Johnson at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Peng Shuai, of China, returns a shot to Venus Williams at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Rafael Nadal, of Spain, reacts after winning a point against Fernando Verdasco, of Spain, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. Nadal won 6-3, 7-5. (AP Photo/Mark J. Terrill)
Venus Williams returns a shot to Peng Shuai, of China, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Kei Nishikori, of Japan, serves to Gilles Muller, of Luxembourg, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. Nishikori won 6-2, 6-2. (AP Photo/Mark J. Terrill)
Gilles Muller, of Luxembourg, returns a shot to Kei Nishikori, of Japan, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Fernando Verdasco, of Spain, returns a shot to Rafael Nadal, of Spain, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Rafael Nadal, of Spain, reacts after losing a point to Fernando Verdasco, of Spain, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Fernando Verdasco, of Spain, returns a shot to Rafael Nadal, of Spain, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Rafael Nadal, of Spain, returns a shot to Fernando Verdasco, of Spain, at the BNP Paribas Open tennis tournament, Tuesday, March 14, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Naomi Osaka, of Japan, returns a shot to Madison Keys at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Madison Keys returns a shot to Naomi Osaka, of Japan, at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Philipp Kohlschreiber, of Germany, reacts after losing a point to Stanislas Wawrinka, of Switzerland, at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Dominic Thiem, of Austria, returns a shot against Mischa Zverev, of Germany, at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Lucie Safarova, of the Czech Republic, returns a shot to Venus Williams at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Stanislas Wawrinka, of Switzerland, returns a shot to Philipp Kohlschreiber, of Germany, at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Venus Williams returns a shot to Lucie Safarova, of the Czech Republic, at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Angelique Kerber, of Germany, reacts after beating Pauline Parmentier, of France, during the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Angelique Kerber, of Germany, serves to Pauline Parmentier, of France, at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)
Pauline Parmentier, of France, returns a shot to Angelique Kerber, of Germany, at the BNP Paribas Open tennis tournament, Monday, March 13, 2017, in Indian Wells, Calif. (AP Photo/Mark J. Terrill)