NWSL players kneel for anthem as tournament kicks off

Players, wearing shirts that read "Black Lives Matter" lined up at the midline and knelt during the pre-game singing of the anthem.

"We took a knee today to protest racial injustice, police brutality and systemic racism against black people and people of color in America," the teams said in a joint statement. "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."

Kneeling for the anthem made former NFL quarterback Colin Kaepernick a lightning rod for controversy when he began the gesture to protest racial injustice in 2016.

While Kaepernick has been out of an NFL job for four years, his protest has gained backing as demonstrations against racial injustice and police brutality have swept across the United States after the killing of unarmed black man George Floyd while in custody of Minneapolis police in May.

Athletes from an array of sports have backed kneeling for the anthem in peaceful protest when their leagues return from the shutdowns forced by the coronavirus pandemic.

In many cases they're being backed by team and league officials who previously rejected the gesture.

With the NWSL being the first American team sports league to return amid the coronavirus pandemic, the players showed their support for the Black Lives Matter movement.

While plans for the return of the NBA, NHL, MLS and Major League Baseball have garnered headlines, the NWSL on Saturday became the first pro team league in action.

It hasn't been smooth sailing for the tournament, scheduled to run until July 26, with the Orlando Pride pulling out last week after six players and four staff had tested positive for COVID-19.

The tournament is also missing some of the best-known US players, with Megan Rapinoe and two of her US teammates from last year's Women's World Cup champions opting out.

Rapinoe, who plays for the OL Reign, pulled out citing concerns about coronavirus and the compressed schedule. Thorns midfielder Tobin Heath and Utah Royals striker Christen Press also cited continuing coronavirus concerns in deciding to skip the event in suburban Salt Lake City.