After a few years he moved to defense, becoming one of the pillars of Polonia's team as well as its captain.

His debut for the Poland national team occurred in 1930, during a game against Sweden.

Szczepaniak had a toal of 34 caps for the national team, and in most matches was the captain.

[1] Also, he was captain in the 1938 FIFA World Cup game of Poland against Brazil.

The game was played on 5 June 1938 in Strasbourg, France which Poland lost 5–6.