Kadlec played in the
Czechoslovak First League, making his debut in the 1983–84 season for Ostrava-based
TJ Vítkovice. He had a spell at
RH Cheb before returning to Vítkovice, from where he moved to Germany in 1990. Kadlec had an eight-year stint with German club
1. FC Kaiserslautern, where they were crowned
Bundesliga champions in
1991 and
1998, the second straight out of the
second division. Kadlec returned to the Czech Republic 1998, spending three seasons with
Petra Drnovice, He made his club debut in a 0–5 away win on 23 June against local amateur side SK Řečkovice in front of a crowd of 900. Kadlec finished his professional career in May 2002, his last match being a 2–1 home defeat against
Opava. ==International career==