Pakistan spinner Noman Ali was recovering Saturday after being rushed to hospital with acute appendicitis, with the veteran ruled out of the rest of their series against Australia.
The 37-year-old, who did not feature during a heavy defeat in the opening test in Perth, suffered severe abdominal pain on Friday.
"Noman Ali complained of sudden and severe abdominal pain yesterday, leading to examinations and scans in emergency that confirmed a diagnosis of acute appendicitis," the Pakistan Cricket Board said.
"On surgeon's advice, he underwent Laparoscopic Appendectomy today."
Ali, who has played 15 tests, the last of which was against Sri Lanka in July, was "stable and doing fine", but will take no further part in the three-test series which resumes in Melbourne next week.
It is another blow for the visitors after pace bowler Khurram Shahzad was ruled out of the series on Thursday.
The 24-year-old impressed on his debut in Perth, finishing with match figures of 5-128 in the 360-run loss.
But he complained of discomfort and scans showed a stress fracture in the ribs along with an abdominal muscle tear.
Pakistan already had a weakened bowling attack after speedster Naseem Shah was omitted from the tour due to a long-term injury.
Spinner Abrar Ahmed missed the Perth test with leg discomfort, but could return for the second match in Melbourne that begins on 26 December.