Young Victorian batsman Will Pucovski has withdrawn from availability for the first Test against Pakistan, citing mental health issues, adding more uncertainty to the squad announcement later on Thursday.

Pucovski informed Australia A team management he was struggling on Tuesday evening in Perth, the day the hosts collapsed in their first innings to Pakistan in what had been widely billed as a batting trial.

Having previously taken two breaks to deal with his mental health last summer, once when representing Victoria and then during the Canberra Test against Sri Lanka where he was a non-playing member if the squad, Pucovski now joins Glenn Maxwell and Nic Maddinson as players taking mental health leave.

"We applaud Will for having the courage to discuss his situation with team management in Perth," national teams manager Ben Oliver said. "Will's decision not to nominate for Test selection was the right one in the circumstances and one that everyone in the Australian cricket family supports.

"Mental health is a complex issue that unfortunately impacts many young men and women in our society. By Will bravely taking this position, he will undoubtedly inspire others facing similar challenges to speak up and take positive steps towards improving their mental wellbeing.

"The most important thing now is for Will to be given the time, space and expert support that he needs to return to full health as soon as possible. I speak on behalf of everyone in Australian cricket when I say we wish Will the very best in his recovery."

Cricket Australia is open about the fact it has a lot to learn about better handling the mental health of its players. Alex Kountouris, CA's head of sports science, has indicated the governing body is committed to openness about the issue.

"There is much society still needs to learn in relation to mental health, but we know enough to say with great certainty that silence is not the answer," Kountouris said.

"Cricket Australia has committed to being open about the challenges faced in managing mental health. We are putting player wellbeing first and supporting them unconditionally. That's something we're proud of.

"Will has demonstrated great strength in being open about his situation. While no one wants to see a fine young man like Will confronting mental wellbeing issues, we are heartened by the fact he is surrounded by excellent people who will support him. We are all right behind him."