 Early into his international career, he helped the Polish national team win the silver medal at the 1992 Summer Olympics.Born in Warsaw, Kowalczyk played his youth football with local Olimpia and Polonez, joining city giants Legia Warsaw in 1990 at the age of 18.Almost from the very beginning, he was an automatic first-choice; in his weakest season, his first, he only appeared in 11 Ekstraklasa games, but was crucial in helping oust U.C.