Paulo Fonseca cited a loss of "mental balance" that contributed to Milan starting their Champions League campaign with a 3-1 defeat to Liverpool on Tuesday. (More Football News)
Milan made a flying start when Christian Pulisic netted after two minutes and 47 seconds, the earliest the Serie A side had scored in the competition since Alexandre Pato's goal against Barcelona in 2011 (24 seconds).
But two headers from Ibrahima Konate and Virgil van Dijk, both from set-pieces, gave the visitors the lead before Dominik Szoboszlai sealed the victory after the break.
Liverpool dominated proceedings after their early setback, registering 23 shots on goal, 11 of which were on target compared to Milan's eight and two.
Arne Slot's side ended the contest with an expected goals (xG) total of 3.09, while Milan could only muster a tally of 0.61 from their attempts on goal.
Ahead of kick-off, Fonseca expressed the importance of being defensively perfect against the Reds, but upon Espen Eskas' full-time whistle, the Milan head coach was left furious with his side's display.
"We played against Liverpool, who are a huge team," Fonseca began.
"We started well, both attacking and defending, but then we conceded two goals from set plays that changed the game.
"We lost our mental balance because when the team lacks confidence, we develop problems and don’t do what we prepared in training.
"I told the players, you cannot make those mistakes in this kind of game.
"At the same time, I have to admit Liverpool are more of a team right now than we are, we need to keep working to have not 20 good minutes, but 70, 80, 90 minutes playing our football.
"After we conceded the second goal, the team stopped playing, and it became difficult after that.”
Milan's danger man Rafael Leao also endured a quiet evening, despite completing more dribbles (five) than anyone during the fixture.
The Portugal international lost possession 15 times, the most in the Milan side, with Trent Alexander-Arnold coming out on top in their respective duels.
Fonseca reiterated his game plan was for Leao to attack Alexander-Arnold but lamented the lack of service provided to the winger by his midfielders.
“It was something we prepared in the little time that we had, try to put Leao against their right-back," he said.
"We did it once or twice in the match. What we prepared was to send Rafa one-on-one against him and we hardly did it.”