After a discussion with doctors, keeping the players' well-being in mind, the decision was taken to delay the Test.
"The two boards made the decision based on medical advice from the England doctors, which revolved around the players’ health and welfare, agreeing that the England cricket team are able to select an XI for the first of the three ICC World Test Championship matches, which will be played at the Rawalpindi Cricket Stadium," read the statement further.
A final decision will be made on whether to go ahead with the Test on Thursday, and if the players do not recover until Thursday, then the match will begin on Friday, and will continue to be a five-day Test match.
"The two boards also agreed, subject to the England players not recovering well enough to take the field on Thursday morning, then the Test will commence on Friday and will be a five-day match. In this scenario, the schedule of the second Test in Multan and the third Test in Karachi will remain unaffected and will be played as per original schedule i.e. 9-13 and 17-21 December, respectively," concluded the PCB statement.