A senior official of the PCB said the speedster was just being rested keeping in mind "other assignments this year that are much more important".
"There is no other reason involved in us advising the nationals selectors not to consider him for the forthcoming Asia Cup tournament. We got a report from Durham as well as the opinion of our own medical experts who believe he requires proper rest to recover from his rib cage injury," PCB chief executive Rameez Raja said.
Raja said it had been unanimously felt that Shoaib was not fit enough and the Board did not want to force the issue of fitness and availability for the Asia Cup on him.
"We require him for other assignments this year that are much more important. He is carrying an injury that will take time (to heal) and we don't want to have a situation where his injury gets worse because it has not been properly treated," he was quoted as saying in local daily The News.
Defending the decision to rest the player for an event that was 41 days away, he said the bowler's medical reports had confirmed the time he would take to make a complete recovery.
He also said the PCB was in constant touch with the Durham officials and keeping a close watch on Shoaib's fitness.