Following an intense 20-player altercation that broke out during Sunday’s FA Cup match at the Emirates Stadium, Manchester United and Arsenal have been warned that they will be the focus of an investigation. Despite playing more than 70 minutes with 10 men, United won the tense third-round grudge match on penalties.

As he teetered on the verge of losing control in the capital, referee Andy Madley wasn’t afraid to issue yellow cards, booking nine players, including Mikel Arteta.

Diogo Dalot was dismissed on the hour mark after receiving two cautions, which only intensified the already simmering dispute.

After Madley ruled that Harry Maguire had fouled Kai Havertz inside the box, which infuriated United’s players, the beacons came on.

After Bruno Fernandes’ first goal was cancelled out by Gabriel Magalhaes, it gave Arsenal the chance to convert a 1-0 deficit into a lead.

A replay of the minor altercation was cut to a massive altercation in which Alejandro Garnacho struggled with Havertz.

After that, Manuel Ugarte intervened and seemed to force his head into the German forward’s, knocking him to the ground.

Since Madley did not see the incident and there was no VAR in place during the FA Cup third round, the players involved got away with it.

Keith Hackett, a former PGMOL leader and FIFA official, thinks both clubs will face consequences for their inability to manage their players.

And after an FA assessment, Hackett recalled a comparable occurrence from his career that resulted in sanctions as harsh as point deductions.

“The mass confrontation which may have also seen a player headbutting an opponent will be the subject of an investigation by the Football Association,” he stated to Football Insider.

“I was in the midst of a large-scale altercation involving a brawl that involved 21 men years ago.

“Because I might have had a number of people walking toward the tunnel, I chose not to red card anyone.

“I sent the Football Association a thorough report, and after their investigation, both teams lost points. Both teams will undoubtedly face consequences for their inability to manage their players.

“The question that we can ask – if VAR was in operation, that would have been reviewed and the result may well have secured a different outcome.”

For Ruben Amorim, who has found his best midfield combination in the Uruguayan and Kobbie Mainoo, losing Ugarte would be catastrophic.

It might ruin his best day as United’s manager to date.