Atletico Madrid left-back Filipe Luis said Fernando Torres' red card against Barcelona was "totally unjust" and claimed their opponents are "protected."
Torres opened the scoring in the first leg of Atletico's Champions League quarterfina at the Camp Nou on Tuesday.
But the Spaniard then received two yellow cards in the space of six first-half minutes, leaving his side with a tough task to keep Barca at bay.
The European champions eventually broke down Atletico, with Luis Suarez scoring a second-half brace to clinch a 2-1 win ahead of next week's secong leg.
Luis, who felt Suarez should have been dismissed for kicking out at Juanfran, said: "The sending off is totally unjust and changed the game.
"Barcelona are protected. When you play against them you realise that they are a very powerful club.
"You realise the fear when Barcelona could get knocked out. It would hurt UEFA a lot.
"Against Real Madrid there was a similar moment [from Suarez]. I don't know what they have to do for someone to send one of them off.
"Fernando, two fouls, two cards. The referee has not seen many Madrid-Barcelona derbies. There would be eight red cards.
"I don't don't know what [a Barcelona player] has to do to get sent off.
"They sent me off [in La Liga fixture] correctly, but the other team isn't treated the same. That's what hurts."
Luis, though, is optimistic Diego Simeone's men can still turn the tie around, adding: "We have our chances but we know now it is going to be really difficult. But we think we are still alive."
Torres said after the game that he endured "among the worst" days in his career following his dismissal.
Atletico Madrid chief executive Miguel Angel Gil Marin added: "We want the same rules of play. If Torres was a sending off, they must apply the same criteria to Suarez. Football cannot be a dictatorship of the biggest."