After winning the Dutch championship with Willem II Tilburg in 1952 and 1955,[1] he coached SC Enschede and Go Ahead Eagles.

In 1970, he took over the Netherlands national team and was their coach as they qualified for the 1974 FIFA World Cup, besting, among others, their rivals Belgium.

Fadrhonc left the Netherlands for Greece to coach AEK Athens in the 1975–76 football season.

In the UEFA Cup campaign of the 1976–77 season, he is credited with the substitution of regular goalkeeper Lakis Stergioudas with veteran Nikos Christidis in extra-time of the second leg of the encounter against QPR.

His move was justified when Christidis stopped two penalties and AEK went through to the semi-finals.