The right-armer, bowling late in-swinging deliveries at very high pace and having developed an extremely fearsome bouncer, soon became one of the most feared and respected bowlers in the West Indies and, following the defection of many of the West Indian team to World Series Cricket, Clarke made his full Test debut at Bourda Cricket Ground in Georgetown, Guyana, against the touring Australian team on 31 March 1978. Clarke took 6/141 in a convincing debut, before injuring an ankle which kept him out of the rest of the series.