Former Test spinner Ashton Agar will be sidelined for up to four months after being booked for more shoulder surgery.
Victoria's Jon Holland has been drafted into the Australia A squad for their upcoming quadrangular series in Queensland after Agar received the bad news.
Agar underwent surgery in April but re-injured his right shoulder at Western Australia pre-season training.
"Ashton had an appointment with a shoulder surgeon earlier this week and a decision was made to have surgery on his right shoulder," Australian physiotherapist Alex Kountouris said.
"We expect that he will not play cricket for the next three to four months but the timeframes will become clearer as we monitor his recovery from the procedure."
Agar is the second player to miss the tournament after fast bowler Pat Cummins withdrew.
Holland was named in a 13-strong Australia A squad on Friday for their opening two four-day matches against South Africa A, in Brisbane and Townsville respectively.
The quadrangular series is a combination of four-day and one-day matches against South Africa A, India A and Cricket Australia's national performance squad.
Former Test `keeper Brad Haddin will be coach Troy Cooley's assistant for the opening two four-day matches, starting in Brisbane on July 30.
Australia A squad: Peter Handscomb (Victoria, capt), Cameron Bancroft (WA, vice-capt), Scott Boland (Victoria), Jon Holland (Victoria), Jake Lehmann (SA), Joe Mennie (SA), Kurtis Patterson (NSW), Matt Renshaw(Qld), Marcus Stoinis (Victoria), Mitchell Swepson (Qld), Chris Tremain (Victoria), Sam Whiteman (WA), Dan Worrall (SA).