Late last month, their lawyers sent letters to FIFA and the Cup’s Canadian organizers saying they would go to court if necessary if those entities refused to change the fields to grass.

“Singling out this women’s tournament for substandard treatment is a mistake that can and must be corrected,” the letter said.

The players have yet to receive a response to the letter from FIFA or from Canada’s soccer association, which has said that its initial proposal to FIFA included a plan to play on artificial turf and that its fields will meet FIFA standards. Besides, the Canadians have said, other top soccer tournaments have been held on some of the fields with no complaints, including the U-20 Women’s World Cup being played in Canada this month.

Yet the group of players, led by Wambach, isn’t taking no for an answer.

The players aren’t threatening to boycott the World Cup if the issue isn’t remedied, said Hampton Dellinger, one of their lawyers. But he stressed that they would keep pushing the issue if FIFA and organizers continue to ignore them.

The fight here is not really about the downside of artificial turf, of which there are many. The ball rolls faster and straighter and bounces higher on turf than on grass, and sliding is a hazardous proposition, since synthetic turf causes more friction than grass. As the knees, elbows and chins of soccer players everywhere will divulge, the turf can peel back layers of skin, and it may cause concussions because it tends to be less forgiving than grass.

“There’s not a person on the planet that would prefer playing on it, not even Sepp Blatter,” Wambach said, referring to the FIFA president, who last week insisted artificial turf was the future of the sport (though apparently not for men’s championships).