Ukrainian qualifier Lesia Tsurenko withdrew from her third-round match at Indian Wells against Belarusian second seed Aryna Sabalenka after suffering a panic attack following a chat with the WTA's chief executive, she said on Monday.
Tsurenko, who beat Croatia's Donna Vekic 2-6 6-2 6-2 on Friday, pulled out of the tournament shortly before her match against Sabalenka was due to start on Monday, citing personal reasons, organisers said.
"The reason for the withdrawal was a panic attack," Tsurenko later told the Big Tennis Ukraine website on Monday.
"Officially it will be written 'personal reasons', but in fact it is breathing problems and, one might say, hysteria."
The 33-year-old said the reason behind her panic attack was a conversation she had days earlier with the WTA chief executive Steve Simon about tennis's response to Russia's invasion of Ukraine.
"I was absolutely shocked by what I heard. He told me that he himself does not support the war, but if the players from Russia and Belarus (do), then this is only their own opinion, and the opinion of other people should not upset me," she said.
"At the same time, he noted that if this had happened to him and he had been in my place, he would have felt terrible."
Responding to a request for comment, the WTA told Reuters: "The WTA has consistently reflected our full support for Ukraine and strongly condemn the actions that have been brought forth by the Russian Government.
"With this, a fundamental principle of the WTA remains ...which is ensuring that individual athletes may participate in professional tennis events based on merit and without any form of discrimination, and not penalised due to the decisions made by the leadership of their country."
Tsurenko added that the WTA boss expressed his confidence in the Russians and Belarusians returning to the Olympics.
"When asked if he understood what he was saying to me during the active phase of Russia's military aggression in my country, he said yes, and this was his opinion," Tsurenko said.
Tsurenko said her conversation with the WTA chief took place before her second-round victory against Vekic.
"I really hope that I will be able to digest all this information and be better prepared for the next tournament," she said.
Tsurenko added that Ukrainian players had requested a conference call with the WTA Board of Directors to discuss the governing body's leadership and their related concerns.