Iker Casillas declared after Real Madrid's 1-1 draw with Manchester City that his side had been hard done by the referee.
Referee Gianluca Rocchi awarded City a penalty with 17 minutes remaining after Álvaro Arbeloa was judged to have grabbed Sergio Agüero's shirt in the box, and the full-back was given a second yellow card for the incident and sent off. Cristiano Ronaldo was also denied a penalty claim.
"It's true that we felt a bit aggrieved by some of the referee's decisions," said Casillas in a post-match interview. "The penalty was very harsh, it wasn't a clear goalscoring chance and that changed the game."
The Madrid captain agreed that his side struggled a bit towards the end of the game.
"We played worse after the sending off. We were ahead in the game but the foul turned the match on its head, a red card and a penalty. That cost us the victory and although we wanted to fight for first place, it wasn't meant to be, but now we've qualified.
"We had a couple of chances to finish the game off before the penalty, but the most important thing is that we have got through a very difficult group. We wanted to get through to the next round and we've done that."