Opener Phil Hughes has pulled out of the Big Bash as he attempts to end a poor run of form that has put his Australia Test spot in doubt.
The 23-year-old has averaged a modest 27.69 runs in Test cricket since fellow batsman Simon Katich was axed from the squad in June.
Hughes was caught in the slip cordon by Martin Guptill off Chris Martin in all four innings of the recent Test series, as New Zealand exposed his weakness outside off stump and his place for the Boxing Day Test against India is under threat.
He had signed up to Sydney Thunder and was set to face Melbourne Stars at the MCG on Saturday but has pulled out.
Hughes said: "Following my performances over the last few months, I have decided that, right now, I need to be completely focus on my first-class cricket career.
"I'm obviously disappointed that I haven't been able to score the runs in the last few Tests that I know I am capable of and I want to do everything I can to ensure that my game continues to develop.
"I talked with Pup (captain Michael Clarke) and (coach) Mickey Arthur about it after the Hobart Test and they both supported my thinking.
"I then approached John Dyson (Sydney Thunder) and Pat Howard (Cricket Australia) to ensure that they would be comfortable for me to step away from my contract with the Thunder.
"Selfishly, it's the right decision for me but I'm obviously concerned that I have made this decision on the eve of the Thunder's first game.
"Everyone has been extremely understanding and I wish the boys all the best for a successful Big Bash season."
Cricket Australia's general manager of team performance Pat Howard added: "Phillip Hughes has taken a decision in the interests of his personal development, to focus on the long-form of the game," .
"Phillip, in close consultation with CA and Sydney Thunder, has decided not to compete with the Thunder this season."
On Monday Hughes will line up for the Chairman's XI in their three-day tour match against India at Manuka Oval in Canberra.