Popp's career highlights are making the quarterfinals of Wimbledon (by far his most successful tournament) in 2000 (defeating Gustavo Kuerten and Michael Chang en route), and in 2003 (defeating Jiří Novák).
In Popp's career, notable achievements include reaching the quarterfinals of Wimbledon (his most successful tournament) in 2000, where he outperformed Gustavo Kuerten and Michael Chang to advance, and also in 2003 when he defeated Jiří Novák.