Razzaq injured a calf muscle in the final one-day international against the West Indies in Karachi on Dec 16 and PCB director of cricket operations Saleem Altaf confirmed that the player had a grade two tear.
''Doctors say he requires at least four weeks of complete rest and cannot train. That rules him out of the first two Tests,'' Altaf told reporters.
''He will be lucky to be fit for the final Test.'' Pakistan play three Tests at Centurion (Jan 11), Port Elizabeth (Jan 19) and seven days later in Cape Town.
They will also play a Twenty20 international and five one-day internationals in February before travelling to the World Cup in the West Indies.
The 27-year-old Razzaq is one of Pakistan's most experienced players, making 46 Test and 224 one-day international appearances for his country.