The Real Madrid midfielder was booked for a rash 38th-minute challenge on Bastian Schweinsteiger during the 4-0 semi-final win over Bayern Munich on Tuesday night and will now miss the showpiece on May 24 after also picking up a caution in the quarter-finals against Borussia Dortmund.
The rules on yellow cards came in for some criticism in 2012 after six Chelsea and Bayern players were banned for the final after picking up yellow cards in the semis and Alonso admits he is not a fan of the disciplinary procedures.
"It's a shame not being able to play in it but I hope my team-mates will win it and with time I'll forget it," he told Real's official website.
"More than being an unfair card, I think it's an unfair rule. The road to the final is very complicated.
"Let's hope we do well and we can win it because the fans really want to play in a Champions League final."
Team-mate Cristiano Ronaldo scored twice in the win at the Allianz Arena to take his tally for this season's Champions League to a record 16 goals and help guide Los Blancos to a first final in 12 years.
Real will be going in search of a 10th European Cup when they walk out at the Estadio da Luz and, after losing in the semi-finals for the past three seasons, Ronaldo is delighted to be contesting a final in his home country.
"We showed a very good attitude and we deserved to reach the final," he said.
"I'd like to thank all the players for their effort and now is time to enjoy the moment and play the final to win. We have been losing in the semis for a long time, three or four years, but the most important thing is that now we are in a deserved final and we have our feet on the ground.
"Since the Champions League started we have taken it step by step and match by match."
On his own personal landmark, the 29-year-old added: "I was looking for it and I knew I needed one goal but I was not going to be mad if it didn't happen.
"It was a great ball from (Gareth) Bale. The whole team helped me.
"I'm really happy to break the Champions League record but what I want is to win it and we're very excited."
Sergio Ramos got the ball rolling for Real with two goals in four first-half minutes but, much like his team-mate, was quick to deflect praise to his team-mates.
"The goals aren't important, the personal side of things is gratifying but the most important thing is the collective job," he said.
"We came to give our all and that's what we did. It was a deserved result and deserved for Real Madrid against the reigning champions of Europe, and this is where Real Madrid has to be, on a world level. This victory has the seal of Real Madrid."
He added: "It is a dream because I've never had the chance to play one. I was waiting for it and now the dream can come true by winning it.
"I want to thank the Madrid fans who have been with us all the way and have come to Munich and all those at home enjoying this too."
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