Major League Baseball's coronavirus-delayed season got underway on Thursday with players lining up to take a knee in a gesture of solidarity with the Black Lives Matter movement.

Four months after the COVID-19 pandemic shelved the start of the 2020 campaign, baseball returned with the Washington Nationals hosting the New York Yankees before the Los Angeles Dodgers entertained the San Francisco Giants.

Both games took place in eerily empty ballparks, a striking contrast to the celebratory atmosphere that normally accompanies the opening day festivities of the sport regarded as America's pastime.

At both Nationals Park in Washington and Dodger Stadium in Los Angeles, players took part in a pre-game tribute to Black Lives Matter, dropping to one knee while lifting a giant black banner in unison.

As the players knelt, a message addressing social injustice recorded by actor Morgan Freeman played on stadium screens.

In Washington, all players on the field then got to their feet to stand for the US national anthem.

The New York Yankees and the Washington Nationals kneel in a moment of silence for Black Lives Matter at Major League Baseball's season-opening game
The New York Yankees and the Washington Nationals kneel in a moment of silence for Black Lives Matter at Major League Baseball's season-opening game GETTY IMAGES NORTH AMERICA / Rob Carr

But in Los Angeles, the Dodgers' newly signed African-American star Mookie Betts remained on one knee, with teammates Cody Bellinger and Max Muncy each resting a supportive hand on his shoulder.

Several members of the Giants' playing and coaching staff also knelt during the anthem.

"It was a really important, unifying moment for the players and staff on both sides," said Giants manager Gabe Kapler, who was among those who knelt.

"It was good to be around players who are so committed to changing the current state of systemic racism in our country."

US infectious disease specialist Anthony Fauci throws the ceremonial first pitch at the Washington Nationals' game against the New York Yankees to open the Major League Baseball season.
US infectious disease specialist Anthony Fauci throws the ceremonial first pitch at the Washington Nationals' game against the New York Yankees to open the Major League Baseball season. Washington Nationals Baseball Club /

Taking a knee has become a widely recognized symbol of support for Black Lives Matter, adopted by protesters and professional athletes around the world in the weeks since the protests erupted.

Kneeling was first used as a gesture of protest by former NFL player Colin Kaepernick in 2016, who was vilified by President Donald Trump for his protests against racial injustice.

Thursday's season-opening games marked a long-awaited return to baseball after months of uncertainty during the coronavirus shutdown that at times threatened to scupper the entire season.

After bitter wrangling between team owners and players, an abbreviated 60-game season was mandated by MLB commissioner Rob Manfred.

Games are taking place without fans, while players are subject to a range of strict health and safety protocols designed to prevent outbreaks of COVID-19.

Players will be tested for the disease every 48 hours, while masks will be mandatory for all players not on the field of play.

As well as strict social distancing, two staples of baseball -- chewing tobacco and sunflower seeds -- are also effectively banned. Under baseball's new safety code, any spitting is forbidden.

Thursday's game in Washington, meanwhile, was marked by an appearance from US infectious disease specialist Anthony Fauci, a devoted fan of the World Series-winning Nationals, who tossed the ceremonial first pitch to get the season underway. Fauci's pitch went way wide of the catcher.

COVID-19, meanwhile, struck a blow to the Nationals earlier Thursday after it emerged star outfielder Juan Soto had tested positive for the disease.

Nationals general manager Mike Rizzo said Soto faces an indefinite spell on the sidelines as he recovers.

Soto's absence was felt on the field by Washington, who slumped to a 4-1 defeat in a game that was called off after torrential rain halted play after the 5th inning with the Yankees leading.

In Los Angeles, meanwhile, the Dodgers romped to an 8-1 defeat of San Francisco.