Shoaib Akhtar and Mohammed Asif have been advised futher rest for two weeks to allow time for their injuries respective injuries to heal properly.
Shoaib's knee troubles and Asif's elbow injury forced their withdrawals from the World Cup and they have been advised to rest for a couple more weeks before they can return to training.
"They need at least two more weeks of rest before they are examined again by our medical panel," Zakir Khan, the board's director of cricket operations, told Reuters.
"The medical panel will decide when they can resume training," he added.
The bowlers tested positive for a banned steroid last October in out-of-competition tests conducted by the board. They were initially banned but then cleared by an appeals panel a month later.
At the time there was intense speculation that they were pulled out of the tournament because of fears that the may still be carrying traces of the steroid Nandrolone in their bodies and thus may have tested positive in the Caribbean. The PCB has consistently rubbished the speculation.
In the absence of the new-ball duo, Pakistan crashed out of the World Cup after successive losses to West Indies and Ireland.