Tim Paine has taken an indefinite mental health break from the game which means he is unavailable for the start of the Ashes and raises the prospect that he has played his last Test.
Paine had been due to play in Tasmania's Marsh Cup game on Friday before linking up with the Australia squad in Brisbane but withdrew from the match on Friday morning following his return to play in the 2nd XI match against South Australia during the week.
"Confirming that [Tim Paine] is stepping away from cricket for an indefinite mental health break," Paine's manager James Henderson tweeted. "We are extremely concerned for his and Bonnie's well-being and will be making no further comment at this time."
A Cricket Tasmania statement said: "Following discussions over the last 24 hours, Tim Paine has advised Cricket Tasmania that he will be taking a leave of absence from all forms of cricket for the foreseeable future.
"Cricket Tasmania will continue to support Tim and his family both professionally and personally over the summer."
Cricket Australia chief executive Nick Hockley said the organisation would offer Paine support.
"We recognise that this is an incredibly difficult time for Tim and his family and are committed to supporting them," he said. "We respect and understand Tim's decision to have a break at this time to focus on his and his family's well-being."
Paine's withdrawal means a likely Test debut for Alex Carey at the Gabba although he could face competition from Josh Inglis. "The National Selection Panel will meet in the coming days to discuss the final squad ahead of the first Ashes Test," Hockley added.
In a joint statement from chair Greg Dyer and chief executive Tood Greenberg, the Australian Cricketers' Association said they were "saddened" by the development.
"First and foremost, the thoughts of the players and everyone at the ACA are with Tim and Bonnie," the statement said. "Family and health are more important than any game of cricket. It takes genuine courage to both recognize the need for help and to ask for it. Tim now needs some time and space and we support his decision.
"Tim made the decision to stand down from the captaincy with the best interests of the game at heart. We hope now that Tim's best interests will also be respected."
When Paine resigned the captaincy a week ago, the Cricket Australia board said he remained available for selection as a player and Paine himself restated his desire to face England despite the fallout.
"I wasn't going to retire, I'd been pretty clear I wanted to keep playing, and potentially finish after this Ashes series," he told the Herald Sun. "I see that as the ultimate high, to be able to finish your test career after winning an Ashes series in Australia. That's the dream. That's what I want to do. To go and represent my country, well, and help win the Ashes."
The ACA, who in their initial statement said they did not believe he should have had to resigned, insisted he had to be allowed to continue playing.
Earlier this week Cricket Tasmania took aim at CA, whose current chair Richard Freudenstein said this board would not have endorsed Paine as captain three years ago, by saying the treatment of him had been the worst of any Australian captain in 50 years.
Paine has played 35 Tests, all but four of those since his comeback after a six year gap when he was recalled for the 2017-18. A few months later he was rushed into the captaincy following the ball-tampering scandal in South Africa. He has lost two Test series at home against India but did retain the Ashes in England during 2019.
Australia's new Test captain may be confirmed on Friday with Pat Cummins the favourite to take over from Paine