The U.S. Soccer Federation has filed a motion opposing the U.S. women’s national team request to certify the players’ lawsuit seeking equitable pay as a class action.

The women filed its motion for class certification on Sept. 11, asking the court to include all players called up to the national team in the lawsuit, in addition to those originally named. U.S. Soccer filed its response to the request on Monday night.

Twenty-eight players, including Alex Morgan and Megan Rapinoe, sued U.S. Soccer in March alleging institutionalized gender discrimination that includes inequitable compensation compared to players on the men’s national team.

U.S. Soccer maintains that compensation for each team is the result of separate collective bargaining agreements, and that the pay structures are different as a result. Men’s team players are paid largely by appearance and performance, while the contract for the women’s team includes provisions for health care and other benefits, as well as salaries in the National Women’s Soccer League.

The federation argued in its motion Monday that four players for the U.S. team — Morgan, Rapinoe, Carli Lloyd and Becky Sauerbrunn — were each paid more than the highest paid player on the men’s national team in four years over the period between 2014-2019. The four earned more even when NWSL salaries were removed, the motion said.

U.S. Soccer maintains that because those players made more they lack the standing to represent a class.

Representatives for the players did not immediately respond to comment Monday night.

The motion says the four players made more in 2015, and then from 2017-2019 than the highest-paid men’s player in each of those years.

The men’s team did not make the field for the 2018 World Cup in Russia and had fewer matches, and therefore fewer call-ups and training camps from 2017-18. The team has also transitioned to new coach Gregg Berhalter, who was hired last December.

The women’s team won this year’s World Cup in France and had additional games leading up to the event, including qualification matches. The women also won the World Cup in 2015. The team also played in victory tour matches following those World Cup victories.

The lawsuit accused the federation of paying players on the women’s team less than similarly situated male national team players on a per game basis.

Following a failed attempt to mediate the matter, a May 5 trial date was set in U.S. District Court in Los Angeles.