The Football Association has launched an investigation into the trouble during Newcastle's friendly match at Huddersfield on Tuesday.
Up to 20 players were involved in a half-time incident after Magpies defender Habib Beye clashed with the Terriers' Andy Butler and Peter Clarke.
Then at full-time Newcastle defender Fabricio Coloccini tangled with Huddersfield striker Lee Novak.
Referee Jon Moss included details of the incidents in his report.
An FA spokesman said: "It has been reported to us and we are looking into it."
Senegal international Beye is understood to have picked up an injury in the scuffle at half-time and is believed to be a doubt for Newcastle's game at Leyton Orient on Saturday.
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