Graham Potter's incredible reaction to Kai Havertz's bizarre handball was caught on camera - with the Chelsea boss stunned by his striker's decision.
Upon seeing the handball, Potter could be seen saying 'f*** me!' to his staff on the bench as he could not believe what he was seeing.
Chelsea were trailing 1-0 to Manchester City when the 23-year-old was taken over by a moment of madness and decided to punch a cross away.
Julian Alvarez converted the penalty for Manchester City to put his side 2-0 up in the tie, before Phil Foden made it 3-0 before half-time.
As a result of the scoreline and Havertz's baffling decision - the Chelsea striker was then dragged off at half-time by Potter.
Fans on social media seem to share Potter's bemusement and took to Twitter to express their confusion.