"With anyone who has surgery there is always a risk that things can go wrong or take longer than expected," the Sydney Morning Herald quoted Kountouris, as saying.
"It's really up in the air. To be honest, until they go in and see how much damage there is and what's going on, it's pretty hard to say what the prognosis is. I would expect that he would come back and play and be right to go. Others have had similar surgery in the past and done well, so there's no reason for him to be any different," he added.
An operation would likely keep Clark from bowling for six weeks, but a complete recovery could take another month.
Only four Australian pace bowlers have bowled past the age of 35 - Ray Lindwall, Keith Miller, Jeff Thomson and Glenn McGrath.
Clark, who is 10 victims away from 100 Test wickets and has a wonderful record against the Proteas, was understandably distraught to miss the heavyweight clash.
"Playing South Africa in this Test match and the two best Test matches of the year in Sydney and Melbourne against the second-best team, and we're the number one team, what can you say?"
Source-ANI
PRI/L