The FA are reportedly looking into an incident which took place between Gabriel Magalhaes and Jordan Henderson in Arsenal's 3-2 Premier League win over Liverpool.
The Gunners rose back to the top of the Premier League table with victory over the Reds at the Emirates Stadium, but the game was not without controversy from the very first minute.
Gabriel Martinelli gave Arsenal the lead with just 58 seconds gone, but it has since been revealed that a possible offside check on Bukayo Saka could not be completed due to a technical error.
The ball then struck Gabriel on the hand in the penalty area from close range in the first half, although a spot kick was not awarded as Darwin Nunez and Saka scored before the end of the first half.
Roberto Firmino levelled proceedings for Liverpool once more before Thiago Alcantara was penalised for a foul on Gabriel Jesus inside the area, as Michael Oliver pointed to the spot.
Before Saka stepped up to convert the game-winning penalty, heated words were exchanged between Gabriel and Henderson, who were both spoken to by referee Oliver.
Jurgen Klopp and Mikel Arteta were also briefed on the incident, while Oliver also spoke with Gabriel and Henderson to get their version of events after the full-time whistle had blown.
Now, Sky Sports News reports that the FA has begun to "gather information" from the pair on the Emirates fracas, and Oliver's referee's report is also being looked at.
The FA are yet to open a full investigation into the matter, and the report adds that it still remains to be seen whether they will do so or take further disciplinary action.
During the initial stages of gathering information, the FA are expected to contact all available eyewitnesses from the incident, whether they be players or club staff.
Furthermore, it is said to be "very likely" that the governing body will employ the services of a lip-reader as they seek to get to the bottom of the incident.
Arsenal remain one point clear of Man City at the top of the table following Sunday's win, while Liverpool are now 14 points adrift of Arteta's early pacesetters in 10th place, albeit with a game in hand.
The Reds were dealt no fewer than three injury blows in North London, as Luis Diaz was forced off with a knee injury that will rule him out until after the 2022 World Cup in Qatar.
Trent Alexander-Arnold and Joel Matip were further casualties of that 3-2 defeat, and the pair are now set for two weeks each on the sidelines with ankle and calf issues respectively.
Liverpool will aim to return to winning ways in Wednesday's Champions League clash with Rangers at Ibrox, while Arsenal travel to Norway to meet Bodo/Glimt in Thursday's Europa League tie.