John Mikel Obi talking with referee, Mark Clattenburg
Chelsea have formally complained to the Football Association over alleged 'inappropriate language' aimed at John Mikel Obi by referee Mark Clattenburg.
The complaint refers to an incident in the Blues' 3-2 defeat by Manchester United on Sunday, reports the BBC.
Chelsea complained to the match delegate and the FA subsequently started an investigation.
The club said there was insufficient evidence to support a claim of alleged verbal abuse against another player.
A Chelsea statement read: "This is a result of a thorough investigation carried out by the club, and led by outside legal counsel, of all information available to us including interviews with a number of players and staff.
"Following Sunday's Premier League game against Manchester United, club board members were quickly made aware, upon entering the home dressing room after the final whistle, that there were allegations of inappropriate language directed at Chelsea players by Mr Clattenburg during the game.
"Board members began establishing the details of the allegations, speaking to all relevant players and staff. After those initial interviews it was clear that the matter had to be reported.
"The correct protocol for doing so was to report the incidents to the match delegate, and the club took immediate steps to inform him as soon as he was available. It was not a decision the club took lightly."