South Africa bowling coach Charl Langeveldt says Kagiso Rabada can continue to lead the attack in the absence of Dale Steyn as they close in on a Test-series lead against Australia.
Steyn will miss the remainder of the series with a shoulder injury, but Rabada backed up a stunning effort from the Proteas' batsmen to snare three Australian wickets on day four as the hosts ended Sunday on 169-4, 369 runs behind South Africa.
Rabada accounted for Shaun Marsh and Steve Smith before handing Adam Voges a six-ball roasting that ended in the veteran's wicket.
Requiring six wickets for victory at the WACA, the Proteas will be a bowler short in their quest for victory, but Langeveldt hopes Rabada can pick up where he left off on day four.
"I told him that you will be tested here because Australia play their cricket hard," Langeveldt said.
"I told him that your first season is your easiest season but that the second season people will work you out. He is the type of bowler who wants to improve.
"He is a quick learner and asks a lot of questions and is very knowledgeable about the game.
"[Bowling] 145kmh as a 21-year-old is always exciting.
"Dale Steyn is a massive loss to South Africa but Rabada has done it before [in Steyn's absence] and today he has stepped up again."