Pakistan batsman Azam Khan has been ruled out of the second and third T20Is against West Indies after sustaining a head injury during the scheduled training session.
"A neurosurgeon has recommended an observation period of 24 hours. He will then be reassessed on Monday," the PCB said in an official statement.
His availability for the fourth and final T20I will depend on the reassessment done on Monday.
The last three T20I's between Pakistan and West Indies will be played in Guyana from July 31 to August 3. The first T20I between West Indies and Pakistan was abandoned due to rain.
Windies had earlier defeated Australia 4-1 in the five-match series while Pakistan lost to England 1-2.