Portugal ace Cristiano Ronaldo was left frustrated after his side's World Cup finals campaign opened with a goalless draw with Ivory Coast.
The Real Madrid superstar came close to breaking the deadlock by hitting a post with a long-range effort, although he was also booked for a clash with Guy Demel.
Ronaldo said after the game: "Sometimes it's difficult that the referee doesn't give fouls because he thinks I dived.
"I know the game is very quick and the players are very quick, but sometimes I don't understand the decisions of referees.
"I respect them, but sometimes I don't agree because they don't protect the dangerous players.
"In the first half, someone tackled me and I was given a yellow card. I didn't do anything, but he gave me a yellow card.
"Sometimes I don't understand, but that's football. I know I don't have to react if I get a yellow card.
"I don't want to speak about the referee. I respect the decision and I want to be focused on helping my team and to do my best."