Sharper in pace than most South African bowlers, Pretorius was thrown in at the deep end during last year's home series against Australia.
Nerves had a part to play, but it proved a sobering experience as the world's top Test side capitalised on his rawness and he finished with match figures of 1-132 from 25 overs.
The selectors decided to look elsewhere as a result, so his selection for the tour to England was something of a surprise, especially his inclusion in the one-day squad where any lack of control could cost the side dear.
But Pretorius has done enough in two months of county cricket with Durham to suggest that he could be a handful if the wickets suit him.
In the past he has worked with Allan Donald, and if he is able to put his mentor's advice into practice, this could be the tour which sees him establish himself in international cricket.