Those three weeks in the Netherlands changed everything. Messi claimed the golden ball as the tournament's best player and golden boot (six goals), scoring twice in the 2-1 final victory over Nigeria.
"You go to see Argentina play and you know they will be good," says Mayer-Vorfelder. "Then you see this player Lionel Messi and you think 'hey, who is that?' And you have to consult the start list to pronounce his name. Then he becomes who he is today."
The tournament, which also featured David Silva and Cesc Fabregas for Spain and Pablo Zabaleta and Sergio Aguero for Argentina, was a huge success.
"That tournament got me really excited about under-20s," says Mayer-Vorfelder. "It's fantastic football. A little less technical, little less fear of losing and more unpredictable. [Defending champions] France haven't even qualified this time. It features players on the verge of a breakthrough, or already professional, and it's a great standard."
From Diego Maradona's coronation in 1979, the tournament has been a launch pad for many careers, with almost 600 players going on to play at the senior World Cup.
Mayer-Vorfelder was probably destined to end up working in football - her father is a former chief executive of the German Football Federation - but she initially took a different path. She studied American Literature at university, before an opportunity to work at the 1994 World Cup sparked an interest in sporting events. On an exchange programme in Chicago, Mayer-Vorfelder took a volunteer position with the local organising committee.
"I was picking people up from the airport, helping them find their transport, translating for fans and tourists," recalls Mayer-Vorfelder.
She also worked at the opening ceremony at Soldier Field, where 70,000 people, including then US President Bill Clinton and former Chancellor of Germany Helmut Kohl, watched Diana Ross attempt an awful penalty before Germany beat Bolivia 1-0.
"The atmosphere was fantastic in a country that was not a football country," says Mayer Vorfelder. "[I thought] that's really fantastic, I want to be involved in big sporting events."
She joined Fifa in 1999, and is now one of the most prominent women in the Zurich headquarters. It's perceived to be a male dominated organisation but Mayer-Vorfelder dismisses the idea that Fifa is overwhelmingly patriarchal.
"[It's like working] as a woman everywhere," says Mayer-Vorfelder.
"We now have three women in the [24-strong] executive committee. We would like to have more female executives in sport but it is happening."
She lists many career highlights, from seeing Chilean and Portuguese fans engulf Toronto in 2007 to witnessing Auckland City's heroics last December in Morocco.
"They became a total favourite of the crowds and every match was close. In the game against San Lorenzo the stadium was going wild." Her immediate focus is Tuesday's glitzy draw, which will feature sporting luminaries like Wynton Rufer, Steve Sumner, Ivan Vicelich, Casey Kopua and a performance from Stan Walker.
The destiny and destinations of the 24 participating nations will be decided, giving fans a chance to plan their itineraries.
"Every under-20 tournament has a lot of stories and we are looking forward to the stories we can tell about this one," she said.
"New Zealand has proven to have a really great track record of great Fifa events."
