Celebrities and sports stars took to social media over the weekend to urge athletes from around the sporting world to “take a knee” during the National Anthem, after President Donald Trump said Friday that any players who protest in that manner should be fired by their team’s owners.

Celebrities including Jeffrey Wright, John Legend, Evan Rachel Wood, Sarah Silverman, Kumail Nanjiani, Daniel Tosh, and Ed Asner, and sports stars including NBA player Chris Paul and NFL cornerback Richard Sherman all took to their Twitter accounts to weigh in on the NFL protests.

At a rally in Alabama Friday, Trump said NFL team owners should fire those who disrespect the country by kneeling during the National Anthem, a form of protest popularized by former San Francisco 49ers quarterback Colin Kaepernick at the start of the 2016 NFL season.

The president followed up his Friday comments with several posts to his Twitter account early Sunday: “If NFL fans refuse to go to games until players stop disrespecting our Flag & Country, you will see change take place fast,” he wrote.

But several stars took Trump on directly over the weekend, including HBO’s Westworld star Wright, who tweeted: “Kneel so hard Sunday the earth shakes.”

Kneel so hard Sunday the earth shakes. — Jeffrey Wright (@jfreewright) September 23, 2017

Ahead of his concert Sunday at the Global Citizen Festival in New York City, R&B legend Stevie Wonder said he was “taking a knee for America,” and two knees in prayer for the world and its leaders.

Other celebrities were quick to weigh in on the controversy:

https://twitter.com/kumailn/status/911631390138961921

Every Black player #TakeAKnee

Sign Kaepernick in the next 10 days. No one enter the White [power] House for any reason. #EasyWork. — jesse Williams. (@iJesseWilliams) September 24, 2017

No. I would like to get white supremacists out of the white house. https://t.co/ElBHLt9jbS — #EvanRachelWould (@evanrachelwood) September 23, 2017

You disrespect our flag every time you open your mouth. You don't deserve to even talk about the flag. https://t.co/Z1xJwq4zhb — Chelsea Handler (@chelseahandler) September 23, 2017

The "you're fired" president thinks he's still in a reality show! He’s the one who should be fired https://t.co/EHA5Da4Dk6 — Barbra Streisand (@BarbraStreisand) September 23, 2017

I just want to send some blessings and support to all the players in the NFL… You have a chance to do something really great tomorrow. ✊🏿 — Diddy (@Diddy) September 23, 2017

The White House is again urging the firing of people who exercise free speech to fight for equality and justice. Shameful. — John Legend (@johnlegend) September 23, 2017

I hope Tom Brady’s wife loans him one of her balls because today would be a good day to stand up for his brothers. #PagingBobKraft — Tom Arnold (@TomArnold) September 23, 2017

Imagine how many hours you have to work just to be average in the NFL versus how few you need to be terrible at President. https://t.co/otOfFByWDC — Seth Meyers (@sethmeyers) September 23, 2017

Funny cuz he's a piece of shit heinous stain on our history & @Kaepernick7 is an American hero who actually stands 4 something https://t.co/4uVn6WYY1F — Sarah Silverman (@SarahKSilverman) September 23, 2017

What if every single @NFL player took a knee this Sunday? — Ed Helms (@edhelms) September 23, 2017

I am taking a knee on Sunday. I might need someone to help me up. #TakeAKnee — Ed Asner (@TheOnlyEdAsner) September 23, 2017

If the ratings down, Trump will use it. In solidarity with #TakeTheKnee and the NFL, let's watch as much football as humanly possible. 🏈 — Alyssa Milano (@Alyssa_Milano) September 24, 2017

i would #TakeTheKnee to shit on steve mnuchin's fishlips face pic.twitter.com/q3doFsjo10 — joe mande (@JoeMande) September 24, 2017

I like when people who told me to respect the Confederate Flag last month scream about respecting the US Flag this month. #TakeTheKnee — John Fugelsang (@JohnFugelsang) September 24, 2017

Trump’s comments led to speculation that even more NFL players would take a knee during this Sunday’s slate of games in protest of the president, even though Sunday marks Gold Star Mother’s Day, which honors parents with children who have died in service to the United States.

During an early game in London on Sunday, numerous players from both the Baltimore Ravens and the Jacksonville Jaguars knelt during the National Anthem, including former Raven Ray Lewis.

“We recognize our players’ influence,” Ravens owner Steve Bisciotti said in a statement ahead of Sunday’s game. “We respect their demonstration and support them 100 percent. All voices need to be heard. That’s democracy in its highest form.”

Follow Daniel Nussbaum on Twitter: @dznussbaum