Career
Dirksen made his international debut against Australia in 1963. The 1967 series against France was probably his finest hour, scoring all three of his test tries against them. The French were understandably quite wary of him throughout that series, dubbing him Le Monster (The Monster).
He played for the then Northern Transvaal (now Blue Bulls) and the Oostelikes (Easterns) club in Pretoria, which later merged with Adelaars to form Naka Bulls.
After retiring from playing he qualified as a medical practitioner, and moved to Johannesburg, Krugersdorp.