Pakistan's injury woes went from bad to worse Sunday with off-spinner Abrar Ahmed the third player in as many days to be ruled out of the second Test against Australia.

Ahmed missed their 360-run defeat in Perth with leg discomfort, and while improving, he has not recovered sufficiently to take part in the Boxing Day Test at Melbourne.

"Considering the nature of the injury and the workload required from a spinner in a Test match, Abrar is not yet ready and will therefore not be available for the second Test," the Pakistan Cricket Board said.

"He will undergo a preliminary fitness test on December 25, which will determine his probable return-to-play date."

It follows fellow spinner Noman Ali being hospitalised with acute appendicitis and ruled out of the rest of the three-match series.

Mohammad Nawaz has been drafted as a replacement, the PCB said.

Pace bowler Khurram Shahzad is another injury casualty, sidelined for the last two Tests with a stress fracture in the ribs along with an abdominal muscle tear after impressing on his debut in Perth.