Giovanni Trapattoni believes his Republic of Ireland players' feelings of "fear" and "tension" contributed to their exit from Euro 2012.
Trapattoni's team went into the tournament on a 14-match unbeaten run.
"Fear and tension has meant that we have made mistakes we didn't make in the qualifiers," Trapattoni said.
"I will ask the lads how on earth it is possible, after two games, we have conceded two goals in the opening three or four minutes.
"Something has changed from our qualifying campaign. We can see the weight on the players' shoulders, but I haven't seen this in training and I am very sad about this."
The Irish have conceded within four minutes of the start of each of their four halves of football so far in Poland and Ukraine.
Trapattoni maintains he is surprised by the way his players have performed.
He added: "The mistakes we made here means we have suffered a bit of a psychological blow.
"We don't see fear in training or in our preparations for the tournament. I don't see tensions in the side.
"For the second time, we conceded an early goal and again it throws any tactical plan out of the window."
Trapattoni's side now face Italy on Monday with nothing to play for.
But the veteran manager insists his team will not be easy opposition for his home nation, who have two points from their two games and need a win to maintain their own qualification hopes.
Trapattoni said: "It is my duty to make sure we finish with our heads held high.
"If Italy are to make the quarter-finals, it has to be down to the fact they played well and through their quality and attitude. We need to do our duty."
Fernando Torres's two goals in La Roja's win were his first in competitive international action since finding the net against Liechtenstein in September 2010.
But the Chelsea striker does not believe that his performance means he can now demand a starting place in coach Vicente del Bosque's star-studded side.
"Anyone can play, so it's not a disappointment to be on the bench with the kind of players in the team," he said.
"I was lucky enough today to be selected for the first XI - two goals was nice - but if in the next game the manager decides to play without a striker that's fine.
"The main thing is for Spain to reach the final and win this title again."