Manchester United, who said they would switch off all their official Facebook, Twitter and Instagram accounts, added that they had conducted their own research into online abuse
Manchester United announced on Friday that online abuse aimed at their players had increased by 350 percent since 2019 ahead of the start of a widespread sports social media boycott to highlight the issue.
A coalition of football organisations including the English Football Association and Premier League revealed they would not post on their channels this weekend and the campaign has grown, with other sports bodies, sponsors and broadcasters joining in.
On Thursday, European football's governing body UEFA said it would also be observing the blackout, which will last from 1400 GMT on Friday until 2259 GMT on Monday.
Manchester United, who said they would switch off all their official Facebook, Twitter and Instagram accounts, added that they had conducted their own research into online abuse.
"The analysis has found that since September 2019, there has been a 350 percent increase in abuse directed towards the club's players," United said in a statement.
United added their study had found that 86 percent of the abusive posts were racist, while eight percent were homophobic or transphobic, with the activity peaking in January 2021.
"By taking part in this boycott this weekend, we, alongside the rest of English football, want to shine a light on the issue," said United's group managing director Richard Arnold.
"It will generate debate and discussion and will raise awareness of the levels of abuse our players and our fans receive."
The Premier League club also said they had taken action against six people alleged to have abused Tottenham's South Korean forward Son Heung-min on social media.
"Regretfully, suspensions have been issued, subject to appeal, to three season ticket holders, two official members and one individual on the season-ticket waiting list," the club said.
"This disciplinary action demonstrates the club's commitment to the fight against discrimination on many fronts."
Chelsea said on Friday they had banned a supporter for posting anti-Semitic messages online.
"Following the conclusion of court proceedings in February, the club conducted our own investigation into the matter and has taken the decision to ban the individual from Chelsea FC for a period of 10 years," said a statement from the club.
A wide range of sporting organisations including England Rugby, British Cycling, the England and Wales Cricket Board and the International Tennis Federation are supporting the blackout.
Formula One is not taking part but world champion Lewis Hamilton said he was ready to join the boycott on the weekend of the Portuguese Grand Prix.
The seven-time world champion, who has 22 million followers on Instagram and more than six million on Twitter, said: "I am fully supportive of the initiative.
"And if me also doing it helps put pressure on those platforms in order to help fight against it then, for sure, I am happy to do so."