Former Australian pacer Merv Hughes has warned against underestimating Dale Steyn and his pace, but is confident that Mitchell Johnson will make South Africa struggle during the Test series.
Hughes was delighted to watch Johnson bowl 40 per cent of his Ashes deliveries at chest level, and said the aggression must continue in Souh Africa.
Graeme Smith is Johnson's most celebrated victim - twice breaking the South African skipper's hand.
Hughes lauded Johnson after he went past him to the top 10 Australian wicket-takers of all time with 242. Another seven and Johnson will surpass legend Richie Benaud in seventh spot.
He said moustache or no moustache Johnson is going to be bowling150km/h at the batsmen, News.com.au reports.
Hughes said softening up the Proteas and their tail will prove a greater challenge than the 5-0 summer annihilation of England.
