Darren Lehmann remains confident Mitchell Marsh will prove his fitness for next week's third Test in Cape Town, but the Australia camp has not ruled out drafting a replacement player should the allrounder's recovery stall.
In the wake of South Africa's six-wicket win at Port Elizabeth yesterday, it was revealed that Marsh had sustained a slight groin strain earlier in the match which explained why he was fielding in the unaccustomed position at first slip during the Proteas' second innings.
The fact that he was on the field rather than undergoing rehabilitation treatment yesterday, coupled with the 10-day hiatus before the next Test of the Qantas Tour of South Africa begins at Newlands on Thursday week, means he seems likely to be passed fit to play with the four-game series tied 1-1.
But Lehmann, the Bupa Support Team men's coach, said today a decision on whether a back-up allrounder might be added to the 15-man squad would be made closer to the Test's starting time after Marsh's fitness had been monitored and the state of the Newlands pitch assessed.
"(We are) reasonably confident, but we'll see over the next couple of days," Lehmann said of the 26-year-old as the Australia squad flew to Cape Town where they will enjoy a few free days before returning to training at week's end.
"Medical staff will have a look at him and assess him, and then make a call from there.
"We're hopeful for the next Test."
Marsh, who also forfeited 20 per cent of his match fee for swearing at Kagiso Rabada after the South Africa fast bowler dismissed him yesterday, has been a pivotal player since he returned to the Australia Test line-up in the middle of this summer's Ashes win over England.
Since that Test at the WACA Ground in Perth, only skipper Steve Smith has scored more Test runs for his country than Marsh's 471 (at an average of 67.29) and the allrounder is also his team's second-most productive batter on the current tour behind opener David Warner.
He has also claimed three valuable wickets at a cost of 15.67 runs each in the current campaign and, given the absence of a genuine allrounder in the Proteas' team, he stands as a crucial point of difference in a series characterised by reverse-swing bowling and middle-order batting collapses.
"He's close to (having) made our most runs," Lehmann said of Marsh's importance to Australia's team balance and output.
"We haven't had a lot of runs in the series so far, but he's looking as good as anyone at the moment.
"(With the) ball he was important for us with those couple wickets late on day two (at Port Elizabeth)."
Marsh also claimed the scalp of South Africa century-maker Aiden Markram at a vital stage of the opening Test at Durban which the tourists won by 118 runs, and his absence would leave a significant hole in Australia's starting XI.
Should he remain under an injury cloud as the third Test draws nearer, Western Australia allrounder (and ODI capped) Marcus Stoinis looms as the likely ‘cover player' given his dual capabilities as a middle-order batter and seam bowler.
Stoinis, who has shown impressive bowling form since returning from international duties to the JLT Sheffield Shield competition last month but has not posted a first-class half-century this summer, is in Adelaide with his WA teammates preparing for the Shield match against South Australia that starts tomorrow.
He is part of a 13-man WA squad that also includes fellow seam-bowling allrounder Hilton Cartwright and spinner-batter Ashton Agar for the match at Adelaide's Gliderol Stadium, which has no bearing on the battle for next week's Shield final.
Cartwright, who played the most recent of his two Tests in Chittagong against Bangladesh last September, has also struggled with the bat recently and averages 23.50 in first-class cricket this summer with a top score of 78.
The other option available to Australia's Test selectors if Marsh is unavailable is to revert to a four-man specialist bowling attack and include auxiliary batter Peter Handscomb to stiffen the middle-order, which Lehmann identified as the culprit for the team's defeat at Port Elizabeth.
"It depends what we want, and what we could get in Cape Town," Lehmann said about possible line-up changes for the third Test.
"We'll have to sum that up the next couple of days, once we get there and have a look."
The absence of Rabada, leading wicket-taker in the series to date but suspended from the final two Tests for disciplinary breaches, offers the potential for some respite for Australia's batters who were blown away by the 22-year-old's pace, swing and accuracy during the second Test.
However, Lehmann pointed out that the Proteas still boast a potent pace attack even without their strike weapon and noted that Australia's focus when they return to training will be greater output from their under-performing batters and better bowling plans to South Africa's key player, AB de Villiers.
"For us, it doesn't matter who plays (for South Africa), we've got to play and bat better than in the first two Test matches," Lehmann said in noting that no Australia batter has scored a century so far in the series.
"I don't think we bowled as well to him (de Villiers) as we could have, and that's an area we can certainly improve on.
"We've got to bowl better to him, he's a class player.
"I thought (Dean) Elgar and (Hashim) Amla also showed our blokes a little bit how to get through (in their 203-minute partnership last Saturday).
"As we know, when your bowlers are starting to bowl 25 overs an innings it is starting to get to be tough work.
"You make your runs at the back end against quality attacks, and that's what we've got to get better at."
Qantas tour of South Africa
South Africa squad: Faf du Plessis (c), Hashim Amla, Temba Bavuma, Quinton de Kock, Theunis de Bruyn, AB de Villiers, Dean Elgar, Heinrich Klaasen, Keshav Maharaj, Aiden Markram, Morne Morkel, Wiaan Mulder, Lungi Ngidi, Vernon Philander, Kagiso Rabada.
Australia squad: Steve Smith (c), David Warner (vc), Cameron Bancroft, Pat Cummins, Peter Handscomb, Josh Hazlewood, Jon Holland, Usman Khawaja, Nathan Lyon, Mitchell Marsh, Shaun Marsh, Tim Paine, Jhye Richardson, Chadd Sayers, Mitchell Starc.
Warm-up match: Australia beat South Africa A by five wickets. Report, highlights
First Test Australia won by 118 runs. Scorecard
Second Test South Africa won by six wickets. Scorecard
Third Test Newlands, Cape Town, March 22-26. Live coverage
Fourth Test Wanderers, Johannesburg, March 30-April 3. Live coverage