Manchester United’s Bastian Schweinsteiger could face a three-match ban for his clash with Winston Reid.
The German was seen by the television cameras apparently eyeing Reid before driving his forearm into his throat as United prepared to take a free kick.
Referee Mark Clattenburg missed the incidents – as did his assistants – and that means retrospective action can be taken.
Both Reid and Hammers boss Slaven Bilic accused Schweinsteiger of deliberately assaulting the defender.
Reid said: “He knows what he’s done — he’s elbowed me in the face.
Bilic added: “It’s a clear red card. A straight red without any doubts.”
The Mirror reports that Marouane Fellaini will escape punishment for his apparent stamp on James Tomkins, because the match officials saw the incident.
Clattenburg will be contacted by the FA to make sure he didn’t see the Schweinsteiger incident, before a three-man panel of former referees examine the video evidence.
If they unanimously agree the World Cup winner should have been sent off, he will be ruled out of fixtures against Bournemouth, Norwich and Stoke.