Shaun Marsh has been called into the Australia squad to face South Africa after all-rounder Shane Watson was ruled out of the first Test with a calf problem.
Watson has experienced calf soreness for more than a week, but was expected to feature in the series-opener at Centurion, which starts on Wednesday.
However, Watson has now been diagnosed with a "low-grade muscle injury", prompting Australia to call up fit-again batsman Marsh, who was originally ruled out of the tour with a calf injury of his own.
"Shaun has now recovered from injury and the National Selection Panel has selected him to join the squad in South Africa in light of Shane Watson not being available for the first Test with a calf injury," selection panel chair John Inverarity told Cricket Australia's official website.
Team physiotherapist Alex Kountouris added of Watson: "We just don't think he's going to be right for the first Test. We need a few more days now to let him recover and start up again. It's not a tear but he has got an injury there.
"We've had a scan and it showed he's got a low-grade muscle injury that we've been managing.
"We were hopeful he'd recover, but it needed to be a little bit more advanced than what it is at the moment."
Watson could yet play a part in the second Test at Port Elizabeth, possibly as a specialist batsman.
"Our first priority is to try and get him (Watson) back as a batter, give the selectors that option," Kountouris added.
"Getting him fit to bowl will be more challenging."