Beijing pollution affecting physical condition of players

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Grigor Dimitrov says players are affected by Beijing's pollution during the tournament, while Nick Kyrgios protested the air quality during his semifinal match.

"The toughest part is when you come from Europe, and the first three days are not easy," Dimitrov said following his semifinal defeat to Rafael Nadal. "But what can you do about it -- if you think about it, there is not much you can do."

The Bulgarian explained he and other players could get "a bit of a headache " and "we are coughing a little bit."

"I just know the feeling," he said. "The first three days are absolutely terrible, I think, for everybody."

Kyrgios also protested the conditions to the chair during his semifinal against Alexander Zverev. The Australian said he has asthma, and, complaining he could not breathe, asked for officials to shut the roof.

A few other players have complained about the air quality in Beijing in previous years.