Herrera claimed referee Ravshan Irmatov missed two chances to award Mexico a spot kick with the score at 0-0 in Recife.
In the 64th minute, Mexico midfielder Hector Herrera claimed he was pushed in the box before a follow-up cross hit the hands of Croatia's Darijo Srna but Irmatov was unmoved, and although Mexico went on to win 3-1 to secure a spot in the round of 16, their coach was unhappy.
Mexico had also been denied two goals in their opening game against Cameroon for incorrect offside goals.
"On one play, two penalties," Herrera was quoted as saying by El Informador.
"But the team was calm, with clear purpose and did extraordinarily well."
Mexico struck soon after through captain Rafael Marquez, who headed Herrera's corner into the net, while they doubled their lead with 15 minutes left when Andres Guardado finished off Oribe Peralta's low cross.
In the 82nd minute it was 3-0 when Javier Hernandez snuck in at the back post to score from a corner, while Ivan Perisic's goal with three minutes remaining was nothing more than a consolation for Croatia.
Herrera said his team had shown the world their quality at the Itaipava Arena Pernambuco but added they can still improve ahead of a round of 16 meeting with the Netherlands.
"Today is a happy day because the guys on the pitch proved their worth and what they are made of, but we can still improve," the coach said.
Marquez declared the result was a deserved one for Mexico.
"We had opportunities in the first half, could not be, but the end result was achieved and we were superior," the defender said.
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