In the big match in the Swiss Super League between Basel and FC Zurich on 14 April, one of the nation’s most prolific strikers and colourful characters made his final appearance as a pro. At exactly 12 minutes past three, Switzerland's all-time leading scorer stepped off the footballing stage as a player prior to taking on a new challenge as FC Lucerne sporting director.

In 16 years as a pro, the 33-year-old racked up the goals for the national team, and for Basel and Borussia Dortmund. He scored 108 times in 166 outings with FCB, and 34 in 74 Bundesliga appearances for BVB. spoke exclusively to the “King of the Penalty Box" about his time as a professional, Dortmund's chances in the UEFA Champions League final, and the prospects for the Swiss national team. Alex Frei, how would you summarise your playing career in a few short phrases?
Alex Frei:
I invested a lot of time, I put in a lot of effort, and I gave up certain interests of my own in favour of life as a pro. I was lucky enough to play in three different countries. I had a fantastic time with Rennes in France. Dortmund was probably the most intense period at club level, because the pressure was the highest. And the Basel project, which I took on in 2009, was unbelievably successful.

What were the best and worst moments in your career?
The worst was certainly EURO 2004, and EURO 2008 when I was injured in the first match. Picking out a single highlight is tough, but what I can say is that I had incredible feelings of happiness, and highlights at every club I played for.

Is there a match or a goal you'll never forget?
Lots. Basically, I remember every goal I scored, but there are obviously certain goals which were more important and loaded with significance due to the situation in the match. Two goals in Manchester, and a goal at home to Manchester were magical moments. Or take my goal against Togo at the World Cup. That was possibly my best international appearance for Switzerland in the last two years. I have plenty of memories which I'd call highlights.

In the course of your career, which player impressed you the most, and which coach influenced you the most?
At Rennes, I was coached by Laszlo Boloni, who put his faith in me and helped me make the international breakthrough. I've played with so many unbelievably good players, such as [Kim] Karlstrom or Petr Cech in goal for Rennes, and [Roman] Weidenfeller or [Sebastian] Kehl in Dortmund. Kehl finished second and third at a World Cup, has multiple Bundesliga championship medals, and is about to contest the Champions League final. These are the guys who've shaped me. At Basel it's been Marco Streller, as we made a wonderful strike pairing in my four years there.

You played for Borussia Dortmund from 2006 to 2009. Have you been following BVB's thrilling progress in the Champions League?
Of course! I knew BVB would get past Malaga. The pressure at Signal Iduna Park when the fans get behind the team is so enormous, only the truly great teams survive. Against Real Madrid [in the return leg], Dortmund could so easily have landed a lucky punch, as people call it, then it would have been basically all over from the start. But I do have to say if the game had gone on five or seven minutes longer, BVB would have been knocked out.

How do you rate Dortmund's chances against Bayern in the final?
Borussia Dortmund will win the Champions League!

Why do you think German clubs are dominating European football at the moment? Are the Germans just so much better?
No. Bayern Munich and Borussia Dortmund have developed a playing style which could well set the benchmark for the next two years. But an era like this comes along every two to four years. It's been Barcelona for a long time, but Chelsea signalled the end of the era last season, and this year it's been German teams. Having said that, the potential for German teams looks a lot rosier than for many others.

Spanish teams often favour a ‘false nine’, and the Germans have picked up on that too. Are we looking at the future? Is the old-fashioned centre forward dying out?
The guy who puts the ball in the net will never die out. Goals win matches.

You're Switzerland's all-time leading scorer. Who might follow in your footsteps?
Here in Switzerland it's not like we have a queue of ten strikers, but including our youngsters, we have a few interesting players. I think someone will come along at some point and break my record, but in order to do so, you need to be a national team regular for five to eight years, and get on a run. It would be a huge advantage to be a big figure at club level too. It rubs off on the national team and you have a completely different type of belief in yourself.

How would you assess Ottmar Hitzfeld's approach as national team coach?
Ottmar Hitzfeld has a different playing philosophy compared to [Jakob] Kobi Kuhn. Kuhn probably preferred a more attacking game, and he obviously benefited from a wonderful generation. Under Hitzfeld, you play with more structure and more solid defending. And I do think in normal circumstances Switzerland will qualify for the World Cup in 2014 - and directly too.

What are your views on Switzerland’s Group E?
There's lots of work going on in every country these days. The gaps are closing at the junior levels and in youth development. Basically, the mechanics are the same in every country. The only factor is whether it functions or not, and whether the players perform above the average or not. Nevertheless, you can't say we had no luck in the draw. There were other high-calibre teams who were top seeds, and we could easily have been drawn against them.

“You part with one eye weeping and one eye sparkling," as a German proverb says - parting is such sweet sorrow, perhaps. How tough was it to call time on your career?
I knew back in September or October that I'd hang up my boots in the summer. It’s just happened a little earlier. I'm not sitting there in the stands suffering or thinking I ought to be playing. I have another perspective on the game now. There's a sparkle in both my eyes.