SYDNEY (Agencies) - Under-fire quick Mitchell Johnson is tipped to edge out Peter Siddle for a pace berth as teenage tearaway Pat Cummins moves a step closer to an historic Test debut against South Africa. Skipper Michael Clarke has revealed he believes Cummins is ready for Test cricket, suggesting the 18-year-old may be handed his baptism in the second Test at the Wanderers. Should Cummins get the nod, he will become the youngest bowler in Australia's 134-year Test history at 18 years and 193 days. But the proposed inclusion of Cummins would come at the expense of either Johnson or Siddle, who were both below-par in Australia's eight-wicket loss in the first Test, returning match figures of 1-87 and 1-65 respectively. Johnson was expected to get the bullet but it is understood he will survive ahead of Siddle because his left-arm deliveries offer an extra dimension to the Australian attack. While Johnson bowled poorly in the first Test, he took nine wickets in the lead-up game against South Africa A and most importantly rediscovered some swing. Clarke was seen beside the Wanderers pitch deep in talks with new selection boss John Inverarity, departing chairman Andrew Hilditch and tour selector Troy Cooley. Clarke will make a final call on the morning of the Test, but he conceded Johnson offered Australia a point of difference. "I think him being the only left-armer in our squad certainly helps, but he's got to be at his best, like Siddle, like 'Rhino' (Harris), like Patty Cumins, like 'Copes','' Clarke said. He said he had no doubts Cummins was up to Test cricket, despite having played just three Sheffield Shield games for NSW. "If he is (selected), I'm not bothered that it will be his debut. I think he's ready, he's keen for an opportunity," Clarke said. "It's just whether we can fit him into the XI. I've seen him bowl in the one-dayers, and he played in the Shield final and bowled a lot of overs.