Women's tennis chiefs on Monday pleaded with spectators to show "understanding and respect" when Ukraine players refuse to shake hands with Russian and Belarusian opponents in protest at the ongoing war in their country.
The WTA, which runs the women's game, became the first governing body to acknowledge demands that they publicly explain the reasons for the stance.
Earlier on Monday, Aryna Sabalenka backed Elina Svitolina's call for officials to respond to help shield players from "so much hate".
Victoria Azarenka, from Belarus, was booed off court following her defeat by Ukraine's Svitolina at Wimbledon on Sunday.
As has become common, Svitolina did not shake hands with Azarenka in protest over Russia's invasion of Ukraine. Belarus is a key military ally of Moscow.
Azarenka, who held her hand up in the direction of Svitolina, seemingly in a gesture of respect, left the court to a chorus of boos from some sections of the crowd.
The two-time Australian Open champion said her treatment "wasn't fair".
"I thought it was a great tennis match," she added.
"If people are going to be focusing only on handshakes or the crowd, quite drunk crowd, booing in the end, that's a shame."
Svitolina and her fellow Ukraine players all refused to shake hands with Russians and Belarusians at the recent French Open.
She called on the sport's governing bodies to explain the position of Ukraine players.
"I don't know if it's maybe not clear for people, some people not really knowing what is happening," she said.
"So I think this is the right (thing) to do."