Looking remarkably relaxed and even managing to smile at reporters, the Argentine-raised player added that he had expected to have featured more in the plans of coach Raymond Domenech.
Trezeguet played a vastly differently role on Sunday to the European Championship final in 2000 when his golden goal in extra time gave France victory against the same opponents.
"I accepted my responsibility. It's part of football to accept your responsibility," said Trezeguet, who was the only player to miss in the shootout when his shot hit the crossbar.
ACCEPT IT
"Penalties are part of the game," added the 28-year-old, who replaced Franck Ribery in extra time and whose only start in the tournament was in the first round match against Togo.
"For me, it was a different kind of World Cup. I expected something else, I expected to play a bit more but because of the tactical system it worked out another way. I have to accept it and look ahead."
Trezeguet, son of Argentine footballer Jorge Trezeguet, was born in France but moved to Argentina at the age of two.
He was brought up there and made his professional debut for Platense at the age of 16 before returning to France the following year to play for AS Monaco.
Trezeguet said France had deserved to win.
"I think that even this evening we showed we were a better team than Italy and if we had attacked a bit more we could have won this match," he said.
"But it's part of the game. We have to accept it and work for the future."
"We have to hold our heads high. We know we've had a good World Cup but it was all defined by this penalty."