Ricardo Carvalho believes referees should do more to help Real Madrid team-mate Cristiano Ronaldo.
Ronaldo was unhappy with the treatment he received during Real's 1-0 victory over Dinamo Zagreb in their UEFA Champions League Group D opener on Wednesday night.
He felt there were too many heavy tackles and that match official Svein Moen was 'shameful' for not giving him more protection.
Real defender Carvalho can understand the frustration of his compatriot, who was left needing stitches following one robust challenge, and has called on referees to do more.
"Marcelo was sent off, Cristiano took many hits and we feel we got very little justice from the referee, who left a few things," Carvalho told Real Madrid TV.
"The challenge on his ankle was wrong, and it's natural for him to get angry. A great player like him should get more protection."
Carvalho also responded to criticism of his sudden retirement from the Portugal national team a couple of weeks ago.
The defender reportedly stormed out on the Portugal squad when it was revealed he would not be starting their recent game against Cyprus, before announcing his retirement the next day and saying that he had been 'disrespected'.
National coach Paulo Bento later asked for an explanation and Carvalho has now attempted to make amends by insisting he was always proud to play for Portugal.
He said: "The Portuguese know it was an honour for me to wear the shirt - I love Portugal. I made a mistake and people make mistakes. It's a bad time."