US Soccer has published a lot of information on this topic, which would be very beneficial to add to your pregame.
Often times mass confrontation manifests itself in one of two ways:
Several players confronting the referee, assistant referees (ARs) or fourth official – players are trying to intimidate one or more official(s) to influence a current or future outcome/decision.
Multiple players confronting each other – swarm of players exhibiting aggressive behavior toward each other. Physical contact is often a by-product of the acts.
Mass confrontations where the officials are surrounded and being intimidated by aggressive players, who hope to influence the referee, is never positive, and invokes a negative public image, slows the game down, ignites further aggressive behavior, and ruins the entertainment value of the game. Referees must work to stamp out these types of mass confrontation from the game. The referee team must work diligently to identify the main culprits and address their actions as misconduct (issue a caution – yellow card, or send off – red card).
In general, mass confrontations share many similar characteristics that referees can use to react quickly in handling these situations:
Caused By a Trigger Issue – Typically follows an issue or foul that is sensitive to players like a hard foul in front of the bench, or a foul where player safety is compromised. Be aware of fouls against the goal keeper or play-maker, or the player running to retrieve the ball from the goal after scoring.
Recognize the Trigger Issue – Officials must immediately recognize these flash point triggers. Failure to recognize, or a delay in responding will result in further escalation. Discuss potential trigger points with the crew pre-game and be prepared to address when they arise. Being aware of the teams and players involved can often help in anticipating when flash-points are more likely to result in mass confrontation issues.
Get there to diffuse – Once mass confrontation amongst opponents arises, a member of the referee team must get there immediately to prevent escalation. For each step you are late, it allows one more player to participate.
Separate and disperse – The first official on the scene should work to carefully separate the immediate players. Once three or more players enter the scene, the referee should step back and observe the situation. The two assistant referees should also take a clear vantage point to observe the actions of the players while the fourth official maintains his position and monitors the bench area. This procedure forms a triangle around the confrontation and provides a process to monitor the situation and gather information. As the situation settles, in a positive, non-threatening manner, officials should attempt to channel opposing players into safe zones away from the hot spot.
Prevent others from joining in and observe – All four officials should not focus on the same hot spot or become too involved in gaining control of the situation. As stated above, form a triangle around the situation, observe, and make notes (mental and otherwise). Look for positive ways to prevent other players from joining in as these players often add “fuel to the fire.”
Consult and dispense the appropriate misconduct – Once the situation is under control and players have been channeled to safe zones, the referee team must quickly dispense the appropriate misconduct. The referee should ensure he has solicited the input of the other officials prior to taking action. Violent conduct should be the first line of focus.