Citing pay and benefits concerns, members of the U.S. women’s national hockey team have threatened to boycott the sport’s world championship this year. The tournament starts on March 31 and is being hosted by the United States.

The U.S. team is favored to win, according to an ESPN commentator, but if they refuse to play, USA Hockey has said it will field a back-up team.

The women have earned Olympic medals, world championships, and near-record Olympic TV ratings, but believe they aren’t compensated accordingly, the commentator told NPR March 22. Currently, the women receive about $6,000 over every 4-year Olympic cycle, requiring them to work other jobs, they say. USA Hockey, however, disputes that number, noting that players can receive medal bonuses from the U.S. Olympic Committee.

The team says it’s not all about individual compensation, however; it’s also about equal benefits. The players have requested improved development for the girls’ and women’s game. USA Hockey dedicates $3.5 million per year to boys’ programs but has no equal program for girls, they allege.

In addition, the players have requested the opportunity to play in more games, and better promotion and marketing. They also want disability insurance, permission to fly business class, and the ability to bring guests to competitions—benefits already offered to the men’s team.

The team has been negotiating for quite some time, media reports say. But the final straw apparently was the uniform unveiling for the 2014 Sochi Olympics. Not only were no members of the women’s team invited to the event, but both the jersey—which the men and women both had to wear—bore the men’s team’s two gold-medal years but not the year the women brought home gold. “We don’t believe it was done maliciously,” one of the players told The Washington Post. “We’re just an afterthought.”

Members of the U.S. women’s soccer team recently filed an equal pay complaint with the U.S. Equal Employment Opportunity Commission making similar claims. The women have told reporters that they are in a unique position, however; many organizations do not directly hire players as employees, as the U.S. Soccer Federation does. USA Hockey has made clear that it does not consider its players to be employees.

As of March 17, USA Hockey’s executive director had this to say: “We remain committed to having the players that were selected to represent the U.S. in the upcoming women’s world championship to be the players that are on the ice when the tournament begins.”

Update (3/29/17): The women’s team reached an agreement with USA Hockey on Tuesday. As reported in The New York Times and other outlets, the women’s hockey team members will now, among other benefits, have the same travel and insurance provisions as the men, receive a monthly $2,000 training stipend, and receive larger performance bonuses for winning medals.