Peter Siddle has been diagnosed with stress fractures in his back and will no longer join Nottinghamshire for the 2016 season.
The 31-year-old had previously signed a two-year contract at Trent Bridge, but will now undergo a lengthy period of rehabilitation.
Siddle, who took 37 wickets at 31.48 during his previous spell with the club in 2014, remains under contract at Trent Bridge for the 2017 campaign.
Mick Newell confirmed that he expects to sign a replacement in time for the start of the new season.
“It’s obviously disappointing, most importantly for Peter himself and we wish him well for his recovery,” said the Nottinghamshire director of cricket.
“An experienced overseas bowler is a key position for us and we’re confident of signing a player of sufficient quality in time for the start of the season.”
The Australian camp confirmed that Siddle will also undergo surgery on an ankle problem during his time away from the game.
“Peter returned to Melbourne on Monday and had subsequent scans following the bout of back pain he suffered during the first Test in Wellington,” said Cricket Australia physiotherapist David Beakley.
“Unfortunately those scans have indicated a stress fracture in his lower back.
“He will now require a significant amount of time away from the game with a lengthy rehabilitation process.
“Whilst he is laid off with his current back injury, we will take the opportunity for Peter to have exploratory surgery on his left ankle to investigate and treat the cause of his ongoing ankle pain.
“Once that surgery is complete we will have a better idea of his prognosis and likely rehabilitation time frame.”