"I didn't understand the substitution and feel a little disappointed," Trezeguet told French newspaper L'Equipe.
"We were winning 2-1 and only needed another goal to go through to the quarter-finals. Perhaps we needed to changed something tactically and put another attacker on.
"Ranieri didn't want to, though," Trezeguet revealed. "It's a shame for me and for the team. Now, we'll have to wait and see what happens next year."