Karel Koželuh was a football, hockey and tennis player who defended two National Teams and some clubs of these nations. Koželuh, who from a young age already showed characteristics of genius, always excelled in tasks that required some extra effort. He, however, without much training already managed to excel. First, he played for Austria and then Czechoslovakia while playing for A.C. Sparta in 1923, at a time when Sparta were still looking for a replacement for Václav Pilát.

Koželuh was a player focused on understanding the game, a more technical and tactical side. He, like a good centre-forward from the Czech school, set up plays for his teammates in the attacking line. Koželuh, at the time, was called an attack leader, as the vast majority of actions started with him. He was far from being an individualist player, as he was always looking for the pass. He was a shy shooter, when he had the chance to score he usually passed the ball, almost never shot on goal.

Even without a focus only on football and without many training conditions due to his other professions, Karel Koželuh could have become one of the most outstanding centre-forwards of all-time, but tennis — his passion — ended up taking his pretensions. As early as 1925, when Koželuh was still playing for Wiener A.C., he decided that he would give up football, as he was afraid of getting injured, thus ending his tennis career. Even so, Koželuh still played a few matches of the 1925/26 season alongside another great name in the sport: Imre Schlosser.