The Professional Footballers' Association (PFA) has defended the right of players to take the knee before games after Millwall supporters booed the gesture prior to Saturday's EFL Championship fixture against Derby County at The Den.
Millwall have said they are "dismayed and saddened" by the booing, which happened in the first game played at the stadium in front of supporters following the easing of COVID-19 restrictions. Access is restricted to a maximum of 2,000 home supporters in the current regulations.
Players and officials from both teams have condemned the booing of the players taking the knee and the PFA, the players' union, has issued a statement to say that it continues to support the Black Lives Matter movement and the wishes of players to make the tribute of kneeling before kick-off.
"The decision to take the knee -- as a result of the death of George Floyd in the USA and the global tide of support for the BLM movement -- was a player-led decision in solidarity and support for Black people facing racism," the PFA statement said. "We have all seen players face racist abuse on and off the pitch -- this is not a political issue it is a human rights issue.
"The PFA fully supports the players' right to take the knee, whilst understanding it is the responsibility of the football authorities to continue to push and challenge inequalities in football.
"The closed stadiums have been a respite for players receiving on-field abuse, although it has not stopped continued abuse online."
Millwall highlighted the "immense disappointment and upset" caused by the incident on Saturday, but the PFA has urged to club to now go further and identify the spectators who booed the taking of the knee.
"The perpetrators at Millwall should be easily traced given stadium restrictions and we call on the club to act swiftly to identify the section of the crowd who booed the players," the PFA said.
"Whilst booing is not a crime, it is a sad indictment of the lack of understanding and empathy for the players' fight against racism and discrimination."
Players from Millwall and opponents Queens Park Rangers will take a knee ahead of Tuesday's match.
Both clubs also said that players would "stand arm-in-arm with each other in a show of solidarity for football's fight against discrimination" before the game kicks off at The Den.
In a statement posted on their respective websites, QPR and Millwall added that the two sides would "hold aloft a banner to show their collective commitment towards ongoing efforts to rid the game of racism in a positive move."
Millwall asked their fans to respect the QPR players taking a knee, insisting that "anybody found guilty of racial abuse is banned for life."