UEFA.com: You've played more Champions League knockout ties than the rest of the Porto squad combined. Your experience could be key against Juvents ...

Iker Casillas: Playing so many important games in a prestigious competition like the Champions League, I have experience to call upon and I'm thankful for that. I hope the other players can feel more confident because of that. Of course we're facing a very tough tie; we know Juve are the favourites, but sometimes excitement, desire, effort and bravery can overcome individual ability.

UEFA.com: You used to play for Real Madrid, who are favourites in every game, but it's a bit different at Porto. How does that feel?

Casillas: On the one hand, a little relieved because always being the favourite makes you feel more responsible and it hurts more when you lose. Now we have to be realistic: we're a good team and we're gradually progressing with the help of our younger players. Now we're facing an opponent who's been at a high level for a long time, playing semi-finals, a final, quarter-finals. However, in the world of football, anything can happen. Six or seven months ago, we were in a play-off against Roma ...

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UEFA.com: What has been the importance of the Champions League throughout your career and what does it mean to you now?

Casillas: Playing in a competition like the Champions League is important for a player, it makes you feel much more of a professional in this sport. The Champions League is where the best players in the world come together.

UEFA.com: You achieved so much with Spain, but do your European successes have a special place? I don't know if your career would have been the same without those Champions League successes?

Casillas: I think that's what adds to a player's prestige. Of course winning domestic tournaments like leagues, cups and super cups adds to your standing in your country, but once you take a step forward in Europe and lift that European Cup, I think that prestige extends to the global stage.

It confirms you as an important player who has played in a prestigious competition and won it. In my case, it's happened three times and of course I'm very proud of that and I hope there will be a fourth.

Casillas is a Porto mainstay ©AFP/Getty Images

UEFA.com: Does the tie against Juve come at a time when you are in your best form since arriving in Porto in 2015?

Casillas: Every player knows it takes time to get used to a new city, new surroundings and a new way of life. Of course when you've spent so long in the same place, as was the case for me, it's strange to experience a change of scenery. Maybe I didn't reach the level I wanted last year, I didn't feel completely comfortable.

I haven't been called up to the Spain squad, so I've had more time to focus on my club. I've noticed the effect. First you need to be settled at your club and then, who knows what might happen?

UEFA.coM: As soon as we learned it was Porto v Juventus, everyone said it was Casillas v Buffon. What do you think about Buffon, as a person and as a goalkeeper?

Casillas: I am lucky enough to be three years younger than Gigi. I was 14 when I started and he was 18; I was able to see and appreciate his style and personality. As I grew up, I looked up to him and then we evolved together and we've had similar careers. We've both won a lot and we've often played against each other. I think Italian football won't have another goalkeeper like him.

In Europe and around the world, he's considered one of the best of all time. Ours is a healthy, positive rivalry: we really appreciate each other and playing against him is always a pleasure. He is a player who is known and admired all over the world and he is part of the history of this game.

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UEFA.com: We know you have an excellent memory and an encyclopaedic knowledge of all your matches. Let's go back to when Real Madrid played Juve in the 2002/03 semi-finals, which was your first game against Buffon. You won the home leg 2-1 before losing 3-1 in Turin. What are your memories?

Casillas: Both teams had outstanding players: Trezeguet, Nedvěd, Zidane, Ronaldo, Figo. We won 2-1 in the first leg but deserved a bit more; it could easily have been 3-1 or even 4-1. In the away leg at Juve's old stadium, we had the chance to turn the match around. However, Luís [Figo] had a penalty saved by Buffon, and next thing they were 3-0 up. Then we made it 3-1, we piled on the pressure for 15 minutes and we might have taken it to 3-2 and gone through.