Career
He was capped nine times, scoring one try. He made his international debut against Ireland in 1981 and was part of the ill-fated 1981 South Africa rugby union tour of New Zealand. Oosthuizen quit rugby in 1985, as he was unhappy with the rugby administration at the time.
Along with former Transvaal centre Dries Maritz, he tried to negotiate better financial advantages for their fellow players, which inevitably led to numerous clashes with the powers that be.
He later had to appear in front of disciplinary committee after allegations of receiving payment for playing form the Rand Afrikaanse Universiteit (Rand Afrikaans University, now the University of Johannesburg). He then briefly served as chairman of the now-defunct Randburg Reconstruction Finance Corporation, before getting federal up with the politics of the game.
After his retirement from playing, he went into business and became chairman of a company specializing in financial services. In the early 1990s, he got involved in efforts to restart rugby league in South Africa.