The FA have confirmed they will be looking into Joey Barton's controversial challenge on Sunderland's Dickson Etuhu in the Wear-Tyne derby.
Newcastle midfielder Barton went into the tackle with his studs dangerously high and clashed with his opponent in the immediate aftermath but there was no foul awarded as the first half drew to a close.
The FA can issue a violent conduct charge retrospectively in instances where the match official, in this case Martin Atkinson, does not notice the incident but later flags it up in his report.
If that is the case Barton, who missed the start of the season with a broken metatarsal, could be subject to a three-game ban.
An FA spokesman said: "We will be looking to clarify with the referee whether he saw the incident or not. If not we will review the incident."