Arsene Wenger pulled Manchester City boss Pep Guardiola to one side for an animated conversation just before their sides faced off at the Emirates.
Wenger appeared to have been waiting for the Spaniard outside the tunnel before instigating the heated scene.
Speaking to Metro before the game, the Frenchman claimed that his side were angry going into the match: "We are angry because we lost a final and what it takes is a desire to respond and to do well because these guys are proud and want to win their games.
"There have been questions after the final but finals are like that. We played against a good side. After the final you have to accept you can win or lose."
In relation to their encounter, Guardiola insisted that there was nothing serious about it: "No [there was no problem]…we spoke like always. There was no problem."
The anger of Wenger's players was not evident during the game as they suffered a second 3-0 loss to City within a week.
All three goals came in the first half, which has never happened in a home game for the Gunners during the Premier League era.
Their woes escalated further as new signing Pierre-Emerick Aubameyang saw his penalty saved by City's Ederson in the 53rd minute.
The result leaves Wenger's men 10 points from the top four, leaving the Europa League as their most realistic route into the Champions League.
The loss was also Arsenal's seventh in 2018 in all competitions - more than any other Premier League side in the same period.