Born in Masterton, at the southern tip of New Zealand's north island, Clarke initially made his mark with Canterbury and the Crusaders before defecting to Taranaki in 2007. He played a single season with the Hurricanes before joining the Chiefs, where his leadership credentials became apparent. After captaining Taranaki to the Ranfurly Shield, Clarke was named as part of a two-man leadership group - alongside Liam Messam - by the Chiefs in 2012. His side secured a maiden title and Clarke was singled out for praise by coach Dave Rennie, having played the final on an injured knee.