James Pattinson, touted as the fourth member of Australia's Ashes pace barrage, is out of the 2017-18 Ashes series and faces a clouded future after medical staff confirmed the seriousness of his latest back injury.

In the newest chapter of a sorry saga for Pattinson, a return to bowling has re-aggravated his previous back stress fracture, a matter of months after he was ruled out of the tours of Bangladesh and India due to pain he complained of following appearances in the English county season and then the Champions Trophy.

"Soon after returning from the UK, following the Champions Trophy and his county cricket contract, James presented with back pain," Cricket Australias head of sports science, Alex Kountouris, said. "We made the decision to withdraw him from the Tour of Bangladesh and monitor his pain. He returned to bowling after a period of rest and unfortunately he is still experiencing pain with bowling.

"During this time we have been monitoring him, including regular scans and recent imaging has confirmed that James has begun to re-aggravate his previous lower back stress fracture. As such, he has discontinued bowling as part of his recovery which unfortunately means that he will be unavailable for the beginning of the Sheffield Shield and subsequently Ashes campaign."

At the age of 27, Pattinson has endured multiple stress fractures in his back, which Kountouris said was causing a flow-on effect, in that one part of his spine faces more stress than it would in other cases. This diagnosis leaves Pattinson and medical staff with a difficult road ahead to chart a path back to a more sustainable bowling career.

Earlier this year, Pattinson revealed he had asked not to be considered for selection for the India Test tour in order not to be rushed back from injury. "I had a chat with the selectors before this series, saying that I just wanted to really get through this Shield season," Pattinson said in March.

"I know the last two times I've done something like this, flown over to a series where it's in the balance and there's the potential of me bowling close to 40, 50 overs, which I have - in South Africa in 2014 I did it, and then last year I did the same thing in New Zealand, going in with not a lot of cricket, and it hasn't really turned out very well for me. We didn't want to make that same mistake again, because at 26, if I went over there and did my back again or something, it would be not an ideal thing for the third time."

Much of CA's approach to fast bowlers is based upon the theory that pace bowlers' bodies don't fully mature until around the age of 25, making it vital that they do not develop chronic injuries while still growing. That theory has been governed largely by case studies such as that of Bruce Reid, the left-arm paceman who took on a heavy load for Australia at a young age before losing most of his prime years due to chronic back problems.

"Whilst this is very disappointing that James has re-aggravated this old injury, we are confident that he can recover from this and return to playing," Kountouris said. "However, James' current injury is complex because his history of old stress fractures from his teenage years means there is one part of his spine that absorbs more force than it would normally do.

"This is the area of the current re-aggravation but we are hopeful that we can put strategies in place to help manage this when James returns to playing."

Pattinson, who has previously spoken about the mental toll of long months rehabilitating alone, away from the camaraderie of a cricket dressing room, was distraught at the news. "Obviously I am extremely disappointed with this setback after just getting back into a good run of playing cricket," he said.

"I'm especially disappointed to miss out on the possibility to play in a home Ashes series. Over the next few weeks I will discuss all available options available to me with medical staff, to work out the best plan to prevent this from happening again."

Pat Cummins is presently the only member of the aforementioned quartet to be fully fit, and is currently resting after the ODI series in India. Mitchell Starc is due to return from a foot injury for New South Wales in their next domestic limited-overs fixture, while Josh Hazlewood is in the latter stages of recovery from a side strain. Nathan Coulter-Nile, who bowled impressively in India, is now expected to be a part of Australia's Ashes squad in Pattinson's stead.