Baig underwent surgery on her injured left thumb in Karachi on Tuesday and she has been advised eight to ten weeks rest. Diana got injured during a training session in Karachi on Monday, where the squad is preparing for the tour.
The 23-year-old Baig will now undergo a rehabilitation programme under the supervision of National Cricket Academy's medical panel.
"It was unfortunate that Diana fractured her left thumb during practice yesterday. Thankfully the surgery was a success and I wish her a speedy recovery. Diana has been replaced by Fatima Sana, a young promising fast bowler and I wish her all the best," Urooj Mumtaz, the chief selector of Pakistan women's team said in an official statement released by the Pakistan Cricket Board (PCB).
Fatima recently took seven wickets in as many games in the second inter-departmental T20 Women's Cricket Championship 2019 held at Islamabad.
Pakistan will play against South Africa in a series of three-ODIs (part of the ICC Women's Championship), five T20Is and two warm-up matches.
The tour of South Africa will last for 25 days and the team leaves for South Africa on 29 April.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)