Mitrovic was involved in an incident with West Ham United's Manuel Lanzini in the 80th minute of the Magpies' 3-0 win on Saturday 26th August.
The misconduct was not seen by the match officials at the time but caught on video.
Aleksandar Mitrovic will serve a three-match suspension with immediate effect after he admitted an FA charge of violent conduct and accepted the standard penalty.
Mitrovic was involved in an incident with West Ham United's Manuel Lanzini in the 80th minute of the Magpies' 3-0 win on Saturday 26th August.
The misconduct was not seen by the match officials at the time but caught on video.