The South African batting line up is in much better shape in comparison to England and will prove to be a tougher opponent for Australia during their Test series next month, according to former Proteas ODI and Twenty20 captain Johan Botha.
Hashim Amla, AB de Villiers and Faf du Plessis will enter next month's series having averaged above 60 since the start of 2012. Captain Graeme Smith has averaged 49 in that time while Alviro Petersen and Jean-Paul Duminy are in the low 40s.
By comparison, England's senior five of Alastair Cook, Jonathan Trott, Ian Bell, Kevin Pietersen and Matt Prior all arrived in Australia for the Ashes with their form down markedly from 2011-12 when they were ranked No.1 in the world, The Sydney Morning Herald reports.
Botha wants to see de Villiers take off the keeping gloves and fill Kallis' vacated No.4 slot and uncapped wicketkeeper Quinton de Kock to take over behind the stumps.
He said De Kock has been excellent in one-day cricket and it'd be a smooth transition for him to come into the Test team and bat at seven.
Conceding that there is no player capable of filling Kallis' shoes as a fourth seamer, Botha believes du Plessis and Duminy, with their part-time spin, could enable the Proteas to play a four-pronged pace attack against the Australians.