Mitchell Starc has become the latest young Australian fast bowler to be sidelined with a stress fracture of the lower back, an injury that puts him in doubt for the start of the Ashes series against England.
Cricket Australia issued a statement Monday saying Starc would be unavailable for a prolonged period but couldn't elaborate on the time frame for his return.
The 23-year-old left-arm paceman was sent home from England last month due to back soreness after Australia's 3-0 Ashes series defeat, missing the ongoing limited-overs series.
Starc, who has 12 Test caps, joins 23-year-old James Pattinson and 20-year-old Pat Cummins on the list of young pacemen sidelined with back injuries.
Cricket Australia doctor Justin Paolini said Starc had scans after returning to Australia showed an early stage low back stress fracture.
"His management plan will be determined in the coming days but he is expected to be unavailable for a prolonged period,'' Paolini said.
The next Ashes series starts November 21 at The Gabba in Brisbane.
Starc took 11 wickets in three Tests during the latest Ashes series, when he was shuffled in and out of the bowling attack.
Pat Howard, Cricket Australia's high performance manager, said the injuries to the three young pacemen were unfortunate.
"While it's a disappointing result for Mitch, we know he will bounce back,'' he said.
"Starc, James Pattinson and Pat Cummins are all under 24 years of age and we are certainly well aware that until fast bowlers get into their mid-20s they are more susceptible to injury.
"Historically, we've rarely seen three such promising young fast bowlers come through at the same time and all of a similar age so when they get injured of course that will be disappointing. We're doing our best to minimise longer term injuries, but we are also realistic that such injuries are possible.''
Alex Kountouris, who has worked as physiotherapist with the Australian team for a decade, said managing the young fast bowlers involves thorough planning to try to minimise the spikes in workloads.
"Unfortunately, it's not as simple as bowling 12 months of the year or "just get them to bowl more'' as some people advocate, because we also know that sustained high workloads also predispose players to injury,'' he said.
In the first two Tests of the last Ashes series, he said Australia bowled on eight of the nine match days and delivered 125 more overs than England's attack.
Pattinson "was the youngest bowler playing those two Tests and unfortunately did not cope,'' he said.
"Cricket Australia has arguably the most comprehensive and longest running injury surveillance system in world sport and helps us understand injury trends,'' he said.
"One of these trends is that younger players (under 25) have higher injury rates.''
Jackson Bird was cleared of serious injury after he flew home from England with back soreness and is expected to be available for the Ashes series, when the Australian attack is likely to be led by aging seamer Ryan Harris and Peter Siddle.