Pakistan's highly rated teenage fast bowler Naseem Shah was taken to hospital with an infection and will miss the fifth Twenty20 international against England later Wednesday, said a cricket board spokesman.
The 19-year-old's availability for the rest of the seven-match series will be decided after assessing his medical reports.
"Naseem was taken to hospital on Tuesday night with a viral infection and will not be available for Wednesday's match," a Pakistan Cricket Board spokesman said.
Naseem played the first match of the series and went for 41 runs in his four wicket-less overs.
The series is tied 2-2 after four matches in Karachi. The remaining three are in Lahore.
England are on their first tour of Pakistan for 17 years.