Manchester United reaffirmed their commitment to the inclusion of supporters from "all backgrounds" but said players are "entitled to hold their own individual opinions" after Noussair Mazraoui opted against wearing a warm-up jacket in support of the LGBTQ+ community.
A source told ESPN that Mazraoui cited his religious beliefs as his reason for not joining the initiative, which was organised to coincide with the Premier League's support of Stonewall's rainbow laces campaign.
United players decided against wearing the jackets ahead of kick-off against Everton on Sunday after learning of Mazraoui's position.
United, meanwhile, clarified that Mazraoui and any other player is entitled to his opinion while also confirming their support for the initiative.
United captain Bruno Fernandes wore the rainbow armband during the 4-0 win over Everton while members of the men's and women's squads, including senior men's players Harry Maguire and Jonny Evans, took part in video content to support the campaign.
A statement issued by the club read: "Manchester United welcomes fans from all backgrounds, including members of the LGBTQ+ community, and we are strongly committed to the principles of diversity and inclusion.
"We demonstrate these principles through a range of activities, including support for our Rainbow Devils supporters' club, and campaigns to celebrate our LGBTQ+ fans and combat all forms of discrimination.
"Players are entitled to hold their own individual opinions, particularly in relation to their faith, and these may sometimes differ from the club's position."
United's LGBTQ+ supporters club, Rainbow Devils, have expressed their disappointment that the jackets were not worn.
A statement issued by Rainbow Devils read: "Shortly before the game, Rainbow Devils were informed that these jackets would not be worn. The reason being that one of the matchday squad had refused to wear the jacket on the grounds of their personally held beliefs. Therefore, to maintain the team ethos and togetherness, none of the players would be wearing them.
"This was obviously a great disappointment to Rainbow Devils, but also to all those who had worked hard at the club to deliver this event. ... We respect the right of this player to have his own views, whilst also feeling disappointed that he put the rest of the squad into a position where they felt that they couldn't wear their jackets. We also worry what kind of negative effect this incident might have on any player at the club who may be struggling with their sexuality."