English football was dealing with further allegations of racially offensive language on Monday as Chelsea made a formal complaint about referee Mark Clattenburg.

The official was at the centre of attention in Manchester United’s 3-2 win over Chelsea at Stamford Bridge on Sunday, red-carding Chelsea’s Branislav Ivanovic and Fernando Torres and allowing United’s winner although Javier Hernandez was offside.

But he was also the subject of a formal complaint made by Chelsea about “inappropriate language” allegedly used to two of their players.

Although Chelsea have so far not revealed, which two players were involved, it is understood they were midfielder Mikel John Obi and forward Juan Mata.

Club officials briefed journalists that one part of the complaint concerns a slur of a racist nature while Mikel visited Clattenburg in his room after the game.

The incident comes as Chelsea captain John Terry serves a four-match suspension for using racially offensive language in an argument with QPR’s Anton Ferdinand in a league game last year.

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