Jose Mourinho was "diasppointed" with referee Howard Webb after he failed to send off Mats Hummels during Real Madrid's 2-0 win over Borussia Dortmund at the Bernabeu.
The victory was not enough for the Spaniards to go through as they went down 4-3 on aggregate, with goals from Karim Benzema and Sergio Ramos insufficient for Mourinho's men to progress.
However things may have been different had the German centre-half saw red for a disputed handball on the edge of the area.
"In football you win or you lose," he told ITV.
"I think we could (have won). We had a couple of big chances but as a consequence of the way we were playing in the last part of the match where we risked absolutely everything.
"I think today we were a team with character, a team with desire and we thought we could do it.
"I don't forget the first match and in the first match we were very, very bad and we have been punished because of the first leg.
"I am very sad with one of my favourite referees in the world, I am very disappointed. It is a red card for Mats Hummels, he saw it, everybody saw it but in that moment he was not a ref he was a human being. He thought 'if I give him a red card here, he misses the final'."
Mats Hummels could not hide his excitement after Borussia Dortmund reached the Champions League final.
Hummels, who was a star performer at the Bernabeu, can now look forward with his team-mates to facing either Barcelona or Bundesliga champions and rivals Bayern Munich, who have a 4-0 aggregate advantage in their semi-final, at Wembley.
"We knew if they scored the crowd would get behind them," said the centre-back. "I felt we were in control but it almost went the same way as our game against Malaga in the last round.
"Getting to a Champions League final is a dream come true for all of us. Especially at a famous stadium like Wembley."
Meanwhile, midfielder Kevin Grosskreutz believes Dortmund are worthy finalists after deservedly knocking out Real.
The Germany international, who came on for the injured Mario Gotze in the 14th minute at the Bernabeu, said: "They put a lot of pressure on us and scored two late goals.
"However, we are a great club and deserved to go through. I have not thought about Wembley yet. Let us celebrate now and think about the final tomorrow."