Manchester United's LGBTQ+ Supporters Group have told fans not to sing offensive chants when they host Chelsea on Thursday.
The club have also written to ticket holders warning supporters that 'any one found using offensive language will be prosecuted' while the club will take 'all necessary action against individuals' too.
It comes as recent meetings between the two clubs have been soured with homophobic chants being made while former Everton manager Frank Lampard had abuse directed to him during Manchester United's 3-1 win at Old Trafford in January.
Mail Sport also reported that the FA had written to clubs regarding the amount of abusive chanting that has been overheard in the first half of the season.