By James Oliphant
SOMERSET, N.J. (Reuters) - National Football League players from the Baltimore Ravens and Jacksonville Jaguars knelt and linked arms during the pre-game national anthem on Sunday, hours after U.S. President Donald Trump called on fans to boycott teams that do not discipline players who protest.
At the first game since Trump stepped up his criticism of NFL players, dozens of members of the Jaguars and Ravens did not stand for the anthem and took a knee, a form of protest that began last year over excessive use of force by police against African-Americans.
Mike Tomlin, coach of the Pittsburgh Steelers, said ahead of the team's game against the Chicago Bears on Sunday afternoon that his players would not come onto the field during the national anthem to avoid "playing politics" in divisive times.
The defiant moves came in responses to a series of comments made by Trump over the weekend criticizing players who refuse to stand for the national anthem.
"If NFL fans refuse to go to games until players stop disrespecting our Flag & Country, you will see change take place fast," Trump wrote on Sunday morning on Twitter. "Fire or suspend!"
In a second tweet, Trump, who is spending the weekend at his golf club in Bedminster, New Jersey, said that the "league should back" fans who are upset about the protests.
The form of protest began in 2016 when then San Francisco 49ers quarterback Colin Kaepernick put one knee to the ground during pre-game renditions of the "Star Spangled Banner." Several players have since made similar gestures of protest before games.
Kaepernick initially started his protests last year by sitting during the anthem but when critics said it was a sign of disrespect, he instead took to kneeling.
At a political rally in Alabama on Friday, Trump suggested any protesting football player was a "son of a bitch" and should lose his job.
On Sunday morning, NFL managers, coaches and owners began to weigh in on the escalating feud.
New England Patriots Chairman and CEO Robert Kraft, who has dined with Trump and who the president considers a friend, criticized Trump and defended players' right to protest.
"I am deeply disappointed by the tone of the comments made by the president on Friday," Kraft said on a statement posted on Twitter. Kraft said he supports his players' "right to peacefully affect social change and raise awareness in a manner they feel is most impactful."
Jaguars owner Shad Khan linked arms with team players in solidarity at the game against the Ravens in London's Wembley Stadium. Khan donated $1 million to the Trump inauguration fund.
And Robert McNair, chairman of the Houston Texans team, said that Trump's comments were "divisive and counterproductive to what our country needs right now." McNair also donated $1 million to Trump.
NFL Commissioner Roger Goodell said Trump's comments in Alabama revealed an "unfortunate lack of respect" for the NFL and its players.
As commissioner, Goodell reports to NFL owners, some of whom have supported Trump. New York Jets owner Woody Johnson, a major Trump presidential campaign donor, was confirmed by the Senate last month as Trump's pick to serve as U.S. ambassador to Britain.
The union representing professional football players also rejected Trump's comments, saying it would defend their right to freedom of expression.
National Basketball Association players also struck back against comments by the president on Saturday after Trump clashed with one of the biggest stars in the NBA.
In an early morning Twitter message on Saturday, the president rescinded a White House invitation to Stephen Curry, who had said he would "vote" against the planned visit by the NBA champion Golden State Warriors.
"Going to the White House is considered a great honor for a championship team. Stephen Curry is hesitating, therefore invitation is withdrawn!" Trump tweeted.
Curry told a news conference in Oakland, California: "It's beneath the leader of a country to go that route."
The Oakland-based Golden State Warriors said in a statement the team had intended to meet to discuss the potential visit at the first opportunity on Saturday morning.
On Saturday evening, Oakland As rookie Bruce Maxwell, an African American son of a military family, became the first Major League Baseball player to kneel for the national anthem in open protest ahead its home game against the Texas Rangers.
Singer Stevie Wonder also appeared to evoke protests by Kaepernick and other athletes when he put one knee to the stage during a concert at the Global Citizen Festival in New York City on Saturday.
"Tonight, I'm taking a knee for America," Wonder told the audience as his son, Kwame Morris, helped him down.
Wonder then put his other leg down so that he was kneeling and facing the cheering crowd, with his son doing the same.
"I’m taking both knees," Wonder said. "Both knees in prayer for our planet, our future, our leaders of the world and our globe."
(Reporting by James Oliphant, Barbara Goldberg, Valerie Volcovici and Jonathan Allen; editing by Grant McCool)