Players for the Portland Thorns and the North Carolina Courage knelt during the national anthem Saturday when the National Women's Soccer League opened the Challenge Cup tournament in Herriman, Utah.

Players and coaches wore Black Lives Matter T-shirts in warmups before the game, which was televised on CBS. A substitute player, coaches and the officials appeared to be the only ones to stand during the playing of the "Star Spangled Banner." The players also knelt during a moment of silence before kickoff.

"We took a knee today to protest racial injustice, police brutality and systemic racism against black people and people of color in America. We love our country and we have taken this opportunity to hold it to a higher standard. It is our duty to demand that the liberties and freedoms this nation was founded upon are extended to everyone," the Thorns and Courage said in a joint statement released before the game.

The league said Friday that it would play the national anthem before the Challenge Cup games and that it would support the players in whatever they chose to do.

The NWSL is the first professional team sport in the United States to return amid the coronavirus outbreak. The monthlong Challenge Cup opened Saturday with a pair of games played without fans at Zions Bank Stadium in Herriman. The Courage defeated the Thorns 2-1 in Saturday's opening match. The Chicago Red Stars played the Washington Spirit in the late game.

"Today, hopefully, it was a powerful statement," Courage midfielder Sam Mewis said. "It was an emotional time, and I hope that both teams' message comes through clearly."

Thorns defender Becky Sauerbrunn said: "We made a strong statement and we wanted to kind of maintain that momentum that has been happening and to show official commitment to the cause."

Megan Rapinoe, who plays for OL Reign but opted out of the Challenge Cup, was criticized when she knelt at an NWSL game and a pair of U.S. national team games in 2016. In response, U.S. Soccer adopted a rule that required players to stand. But that rule was repealed earlier this month amid nationwide protests over the death of George Floyd and racial inequity.