Johannesburg - Morne Morkel may be playing his last Test, but South Africa's bowling attack is looking as strong as ever right now. 

It hasn't hurt that three of Australia's top four batsmen have returned home after the ball-tampering incident in the third Test at Newlands, but all series long the Proteas seamers have delivered. 

When play got underway at the start of day three at the Wanderers on Sunday, Kagiso Rabada was the series' leading wicket-taker with 21 scalps. 

Rabada is also currently the No 1 ranked bowler in Test cricket. 

Vernon Philander, meanwhile, picked up three wickets on Saturday and he needs just two more to become the seventh South African in history to take 200 Test wickets. 

Morkel, meanwhile, picked up nine match wickets at Newlands, where he became the fifth South African to reach 300. 

When Morkel departs at the end of the series, South Africa will look to Lungi Ngidi to play more Test cricket while Dale Steyn is also eyeing a comeback. 

In the spin department, Keshav Maharaj is the brightest prospect South Africa have had in some time and he continues to impress with his ability to provide control from one end while he can also pick up big wickets at key times. 

It is safe to say that South Africa looks to be in a good space with the ball, and Australian assistant coach David Saker agrees. 

"I think they've been extremely accurate which is a big factor in being a good bowling attack," he said after watching his side reduced to 110/6 in their first innings in Johannesburg.

"They've got Vernon Philander, who is as accurate a bowler as there is in the world. He also moves the ball, which is a challenge.

"And they've got probably the best strike bowler in the world in Rabada.

"They complement each other very well and their spinner is bowling extremely well as well, but we haven't combatted it well enough with the bat."